Mechanical engineering calculators for machine design
Shafts, gears, keyways, fits, tube deflection, metal weights, springs, fasteners and sheet metal — metric & imperial, each with the formula and standard shown.
Machinist calculator — degree trig, 1/64 fractions, in⇄mm, tape → Square tube Metal weight Keyway Overhung load Hole/shaft fit Pipe bend Pipe miter Planetary gear Involute gear Shaft torsion Countersink Rack & pinion Line size Pull tension Fault current Motor amps Line charge Hydronic BTU Drawer slides Shelf sag Ballast weight PTO horsepower Fuel surcharge Freight density Truckload capacity Axle load Tongue weight Deck beam Rebar spacing Anchor pullout Expansion tank Air receiver Air pipe size Rolling offset Pipe saddle Pipe reducer Gutters Catch basin French drain Swale capacity Culvert Tap drill Ramp entry Hydraulic force Valve spring Compression spring
All calculators Machinist Calculator Workbench · live
Degree trig · 1/64 fraction readout · in⇄mm on every result.
Popular tools
High-intent tools first, with the rest one tap away.
Gears
See all calculators Gear Backlash
Spur gear backlash allowance from module, DP or circular pitch, with angular backlash and tooth-thickness reduction.
Power TransmissionOverhung Load
Overhung shaft load, bearing reactions, load amplification and bending moment from torque, pitch diameter and load position.
MachiningKeyway Dimension
Standard parallel key & keyway dimensions for a shaft per DIN 6885-1.
HydraulicsPipe Miter Cut
Pipe miter cut angle, long-to-short difference and wrap-around template drops from OD, turn angle and miter piece count.
StructuralSquare Tube Deflection
Deflection, stress and I of a square/rectangular HSS tube used as a beam.
GearsInvolute Gear
Tooth geometry from module/DP and pressure angle, with a tooth-profile render and DXF export.
StructuralShaft Torsion
Circular-shaft torsion stress, angle of twist, polar moment J and torque capacity.
Power TransmissionSprocket
Sprocket ratio, RPM, chain speed and pitch diameters for a chain drive.
GearsPlanetary Gear
Epicyclic gear ratio for ring-, sun- or carrier-fixed arrangements.
MachiningCNC Speeds and Feeds
Spindle RPM, feed rate, feed per rev and material removal rate from material, tool, flutes and chip load.
FastenersBolt Preload & Torque
Clamp force from tightening torque and nut factor, with proof-load utilization, target torque and preload scatter.
GD&TMMC Bonus Tolerance
MMC/LMC bonus tolerance from a feature’s departure from its material limit.
GD&THole & Shaft Fit
ISO 286 hole-basis clearance-fit limits and clearance (H7/g6, H8/f7, …).
GearsGear Generator
Generate an involute spur gear profile with live preview and DXF export.
MaterialsMetal Weight
Weight, order weight, material cost, weight-per-length and cross-section area for bar, tube, plate or angle in any metal.
FastenersBolt Shear Strength
Ultimate shear capacity of a bolt from grade, diameter and pitch — thread or shank plane, single or double shear.
SpringsCompression Spring
Rate, Wahl-corrected stress, force, coil-bind travel and buckling, with built-in material data.
HydraulicsPipe Bend Developed Length
Pipe bend centerline arc length and developed cut length from bend angle, radius, OD and tangents, with chord, setback and blank margin.
MachiningCountersink Depth
Plunge depth and chamfer width of a conical countersink from angle, rim and hole diameter.
Power TransmissionRack and Pinion
Rack travel per pinion revolution, linear speed and force from module, teeth, RPM and torque.
MachiningDovetail
Over-pin / between-pin measurement for inspecting a male or female dovetail slide.
MachiningBall Nose Stepover
Scallop height between parallel ball-nose passes — or the stepover for a target finish.
FastenersBolt Pattern Force
Shear load per bolt in a circular pattern under a torsional moment plus direct shear.
StructuralLVL Beam
Preliminary LVL beam sizing from span, plies, depth, uniform line loads and product design values, with bending, shear and deflection checks.
FastenersWeld Throat
Fillet weld throat, throat area, capacity and required equal leg from equal/unequal legs, root opening and ASD/LRFD basis.
Power TransmissionBelt Length
Two-pulley belt length and wrap angle from center distance and diameters.
Power TransmissionChain Length
Roller-chain length in links and mm from sprocket teeth and center distance.
MaterialsKerf Bending
Woodworking kerf-bend cut count, spacing, layout length, cut depth, remaining web and slot-closure screen from radius, angle, stock and saw kerf.
MachiningMachining Time
Estimate CNC feed time, cycle time, batch time and parts per hour from toolpath length, feed rate, RPM, chip load and passes.
SpringsSpring Fatigue Life
Goodman/Zimmerli infinite-life screen from Fmin-Fmax: alternating and mean Wahl stress, endurance line and shot-peening effect.
HydraulicsCompressed Air Receiver Sizing
Compressed-air receiver volume, stored free air, reserve time, utilization and recharge time from demand, compressor FAD and pressure band.
Workflow suites
Curated tool sets for the jobs people actually search for.
25 tools
Cabinetry, furniture, trim, finish and shop airflow Woodworking Plan cabinetry and furniture work from takeoff to finish: board feet, cut lists, panel layouts, drawer sizing, joinery spacing, glue, finish coverage and dust airflow. 24 tools
Decks, slabs, joists, rafters, roof ventilation, stairs, trim and preliminary wood spans Construction Move field dimensions into preliminary rafter, stair, deck joist and beam, slab and footing numbers, with ventilation, fastener and material takeoffs on the way. 10 tools
Fuel, surcharge recovery, pallets, payload, axle loads, PTO power and trailer balance Fleet & Logistics Group route fuel cost, surcharge recovery, freight density, pallet and payload capacity, axle loads and trailer balance into one fleet workflow. 22 tools
Hydraulic, pneumatic, compressed-air receiver and dosing screens Fluid Power Size hydraulic and pneumatic actuators, pumps, receivers and hose runs, then screen drive motor amps, overloads and dosing rates for the same line. 28 tools
Pipe size, hydronic BTU/GPM, expansion tanks, trench backfill, roof and site drainage, trench drains, French drains, swales, sump pumps, culverts, rolling offsets, bend lengths, miter, saddle and reducer layouts, slope, heat loss and supports Piping Trades Size water, drain and hydronic piping end to end: flow and pressure-drop screening, slopes, expansion tanks, water hammer, pipe supports and site drainage. 12 tools
K-factor, bends, blanks, patterns, gauges, tonnage and finishing Sheet Metal Fab Flatten brake work from measured K-factor through bend allowance and deduction, tray and cone blanks, press tonnage and powder-coat coverage. 9 tools
Tap drill, 2A/2B limits, threading passes and over-wires verification Threading Run a thread from print to gauge: size the hole or blank, hold the ASME B1.1 2A/2B limits, plan the cutting passes and verify the pitch diameter over wires. 6 tools
Wire size, COG load share, sling angle, stretch and replacement cut length Standing Rigging Keep sailboat standing-rigging wire size, target tension, load share and turnbuckle checks consistent from spec sheet to dockside tune. 5 tools
Soak, case depth, martensite start and temper — composition to final hardness Heat treat Plan a quench-and-temper from the steel up: austenitizing soak, carburized case depth, martensite start from composition, then temper to the target hardness.
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Each category starts compact. Expand a group or open the full directory.
Compression, extension & rate — Wahl stress, buckling length, material data.
Compression Spring Rate, Wahl-corrected stress, force, coil-bind travel and buckling, with built-in material data. Spring Design Back-solve wire diameter and active coils from target load, travel, diameter and spring index, then re-check the rounded shop candidate. Music Wire Spring ASTM A228 music-wire spring rate, force, tensile strength and corrected stress. Spring Rate Spring rate (spring constant) from wire size, coil diameter and material. Extension Spring Rate, spring index and force at extension including initial tension. Spring Constant Spring constant from two measured load/deflection points (Hooke’s law). Torsion Spring Deflection angle, rate per turn and Wahl-corrected inner-fibre bending stress for a helical torsion spring. Belleville Washer Load Disc spring load at deflection, flat load, OM set stress and series/parallel stack travel by the DIN 2092 (Almen-Laszlo) method. Spring Fatigue Life Goodman/Zimmerli infinite-life screen from Fmin-Fmax: alternating and mean Wahl stress, endurance line and shot-peening effect.
Involute geometry, ratios, mesh forces, bevel, planetary, worm — with DXF profiles.
Gear Generator Generate an involute spur gear profile with live preview and DXF export. Spur Gear Spur gear geometry, undercut warning, center distance and DXF export. Involute Gear Tooth geometry from module/DP and pressure angle, with a tooth-profile render and DXF export. Base Circle Diameter Involute gear base circle diameter, base radius and base pitch from pitch diameter, module, DP or circular pitch. Gear Tooth Involute spur gear tooth thickness, addendum, dedendum, whole depth and undercut margin. Gear Backlash Spur gear backlash allowance from module, DP or circular pitch, with angular backlash and tooth-thickness reduction. Gear Contact Ratio Transverse spur gear contact ratio, path of contact, base pitch and working pressure angle. Gear Ratio Gear ratio with output RPM, torque and vehicle speed from tire size. Pitch Diameter Gear pitch diameter from module, DP or circular pitch and tooth count. Gear Module Module from pitch or outside diameter and teeth, with nearest ISO module, diametral pitch and circular pitch. Gear Tooth Ratio Single- or two-stage gear-train ratio and output speed from tooth counts. Planetary Gear Epicyclic gear ratio for ring-, sun- or carrier-fixed arrangements. Worm Gear Worm drive ratio, center distance, lead angle and self-locking check. Bevel Gear Straight bevel gear ratio, pitch cone angles, cone distance, face width, RPM and torque. Helical Gear Parallel-shaft helical gear ratio, transverse module, pitch diameters, center distance, axial pitch and lead. Span Measurement Over Teeth Base tangent length W over k teeth from module/DP, pressure angle and profile shift, with recommended span count and contact check. Profile Shift Coefficient Minimum shift to avoid undercut, tip thinning checks, working pressure angle and modified center distance for shifted gears. Gear Mesh Force Tangential, radial and axial tooth loads from torque, pitch diameter, pressure angle, helix angle and service factor.
True position with MMC, tolerance stack-up, runout, ISO 286 fits.
True Position GD&T true position from X/Y deviation with MMC bonus tolerance and a pass/fail check. MMC Bonus Tolerance MMC/LMC bonus tolerance from a feature’s departure from its material limit. Composite Position Tolerance Two-tier PLTZF/FRTZF position check from X/Y deviation. Flatness Tolerance Flatness (surface form) from measured points, with a pass/fail check. Hole & Shaft Fit ISO 286 hole-basis clearance-fit limits and clearance (H7/g6, H8/f7, …). Press Fit / Interference Interference-fit contact pressure, assembly force, torque capacity and hub stress (Lamé). Cylindricity & Runout Runout (TIR) and cylindricity zone from indicator and diameter readings.
Speeds & feeds, milling/turning/drilling power, shop rate, machining cost, finish and end-mill deflection.
Surface Feet per Minute Cutting speed (SFM / m·min) and diameter to spindle RPM, with cutting speeds by material. Cutting Speed Convert cutting speed to spindle RPM, or calculate actual SFM / m·min from RPM and diameter. Bore & Stroke Engine displacement (cc / L / ci) and bore/stroke ratio from bore, stroke and cylinders. Tap Drill Size Tap drill diameter for any metric or unified thread at your chosen % thread engagement. Unified Thread Limits (2A/2B) ASME B1.1 limits from diameter and TPI: 2A allowance, major and pitch diameter limits, 2B pitch and minor limits — table-exact, any UNS pitch. Keyway Dimension Standard parallel key & keyway dimensions for a shaft per DIN 6885-1. CNC Speeds and Feeds Spindle RPM, feed rate, feed per rev and material removal rate from material, tool, flutes and chip load. Machining Time Estimate CNC feed time, cycle time, batch time and parts per hour from toolpath length, feed rate, RPM, chip load and passes. Machining Cost Estimate CNC part cost from material, setup, cycle time, shop rate, tooling, secondary work and markup. Injection Molding Shot Size Estimate shot weight, barrel utilization, machine capacity range and clamp force from part weight, cavities, runner weight and projected area. Chip Load Chip load (feed per tooth) ↔ milling feed rate from RPM and flutes — Vf = fz·Z·n. Radial Chip Thinning Compensated feed per tooth and table feed for light stepovers: target chip ÷ √(1−(1−2ae/D)²), with thinning factor and engagement angle. Knurl Blank Diameter Nearest tracking diameter from TPI, diametral pitch or linear pitch: whole teeth around the work, the correction to turn and finished OD. Bandsaw Cut Time Time per cut from section area and the blade chart’s area rate (t = A ÷ Q), round or rectangular stock, bundles, and feed-on cuts per hour. Surface Finish Theoretical turning Ra & Rz from feed and nose radius — or the max feed for a target finish. Tapping Feed Rate Tapping feed rate Vf = spindle RPM × thread pitch; the feed per rev equals the pitch. Peck Drilling Plan peck count, programmed depth, feed time and G83/G73-style retract overhead. Thread Mill Feed Compensate thread-mill feed for helical interpolation — tool-centre from cutting-edge feed. Helical Ramp Entry Plan end-mill helical ramp pitch, turns, path length, entry time and ramp feed from angle, depth and bore or tool-center path diameter. Sine Bar Gauge-block stack for a sine bar set to an angle (or the angle from a stack) — h = L·sin θ. Ball Nose Stepover Scallop height between parallel ball-nose passes — or the stepover for a target finish. Boring Bar Deflection Static tool tip deflection, bending stress, L/D overhang ratio and required diameter for boring bars or cutter stickout. Countersink Depth Plunge depth and chamfer width of a conical countersink from angle, rim and hole diameter. Dividing Head Indexing Crank turns and index-plate holes from a division count or DMS angle — B&S plates or custom circle, any worm ratio. Lathe Change Gear Screw-cutting gear trains for any pitch on any leadscrew — exact via 127, or closest train with ppm error. Dovetail Over-pin / between-pin measurement for inspecting a male or female dovetail slide.
Metal and lumber weight, woodworking calculators, board feet, cut lists, plywood cut optimizer layouts, panel glue-ups, wood glue takeoffs, cabinet doors, drawer boxes, drawer slides, veneer coverage, edge banding, dust-collector CFM, shelf sag, kerf bending, dovetail spacing, mortise and tenon layout, dado/groove layout, wood moisture, wood movement, stain coverage, plywood sheets and stock data.
Metal Weight Weight, order weight, material cost, weight-per-length and cross-section area for bar, tube, plate or angle in any metal. Chvorinov Solidification Time Casting modulus, Chvorinov solidification time, riser time ratio and required riser modulus from volume and cooling area. Shelf Sag Wood, plywood, MDF or particleboard shelf deflection from span, depth, thickness, load, support condition and material stiffness. Drawer Box Size Cabinet drawer box width, height, depth, side panels, front/back panels, bottom panel and interior volume from opening, slide clearance, setbacks and material thickness. Drawer Slide Cabinet drawer slide clearances, box width, box height, available slide depth, rounded slide length, depth reserve and estimated travel. Shelf Pin Hole Spacing 32 mm system shelf-pin layout: hole count, first/last positions and remainder from interior height, pitch and clearances. Kerf Width Saw kerf loss, required stock length, remaining offcut, yield and cut-loss cost from blade width, cut count and repeated part length. Kerf Bending Woodworking kerf-bend cut count, spacing, layout length, cut depth, remaining web and slot-closure screen from radius, angle, stock and saw kerf. Heat Treat Soak Time Hour-per-inch soak rule with austenitize/temper/anneal floors from the governing section thickness.
Cylinder force, rod buckling, oil velocity, pump flow, NPSH, orifice flow, compressed-air receivers, leak cost, compressed-air pipe sizing, chemical feed, pipe sizing, hydronic flow/load, expansion tanks, trench backfill, rolling offsets, pipe bends, miter, saddle and reducer templates, gutters, catch basins, trench drains, French drains, swales, sump pumps, culverts, insulation heat loss, pressure rating, supports, water hammer, volume, slope and pressure drop.
Hydraulic Cylinder Force Push and pull force with the rod-area differential shown explicitly. Standard ISO bore chart included. Hydraulic Cylinder Hydraulic cylinder push/pull force, stroke speed and standard bore sizing. Hydraulic Pump Flow & HP Pump output flow and hydraulic/shaft power from displacement, speed and pressure. Hydraulic Regeneration Circuit Regen extend speed Q/A_rod, available force, speed gain and the combined cap-end flow the lines must carry. Pneumatic Air Consumption Free-air consumption per cycle and per minute for a pneumatic cylinder. Compressed Air Receiver Sizing Compressed-air receiver volume, stored free air, reserve time, utilization and recharge time from demand, compressor FAD and pressure band. Compressed Air Pipe Sizing Compressed-air pipe velocity, pressure drop, outlet pressure and required actual ID from SCFM/Nl/min, pressure, length, roughness and fittings. Hydraulic Reservoir Size First-pass hydraulic tank volume from pump flow, residence time and usable oil fraction. Filter Beta Ratio Beta ratio ⇄ capture efficiency from multipass counts: β = up/down, η = (1−1/β)×100, with particles passed per million. Water Hammer Pressure Pipe surge pressure, wave speed, critical closure time and pressure-rating margin from flow, pipe geometry, wall thickness and closure time. Pipe Size by Flow Velocity Required pipe inside diameter from flow and target velocity, with Darcy pressure drop and head loss at the solved ID. Pipe Volume Pipe liquid capacity, contained volume, fluid mass and fill or drain time from actual ID, length, run count, flow and density. Expansion Tank Sizing Hydronic expansion volume, required acceptance, minimum diaphragm tank volume, selected-tank utilization and maximum pressure check. Pipe Slope Drain and pipe layout slope, fall, pitch, end invert elevation, inches per foot and 1:n ratio from run length or invert elevations. Pipe Rolling Offset Pipefitter rolling offset layout from rise, roll, fitting angle and takeout, with true offset, travel, cut length, advance and roll angle. Pipe Fitting Takeout Cut length from center-to-center with ASME B16.9 elbow/tee/cap takeouts at each end plus weld root gaps. Pipe Bend Developed Length Pipe bend centerline arc length and developed cut length from bend angle, radius, OD and tangents, with chord, setback and blank margin. Pipe Miter Cut Pipe miter cut angle, long-to-short difference and wrap-around template drops from OD, turn angle and miter piece count. Pipe Saddle Cut Centered branch-pipe saddle and lateral coping template from header OD, branch OD and branch angle, with 16-mark drops. Pipe Reducer Offset Concentric and eccentric pipe reducer offset, long/short side lengths, taper angles and shell-area estimate from actual ODs and reducer length. Catch Basin Sizing Catch basin and yard-drain runoff, grate open area, inlet velocity, Manning outlet pipe capacity and limiting drainage area. Gutter & Downspout Sizing Roof runoff, gutter run capacity, downspout capacity, required gutter depth and limiting roof area from rainfall and gutter geometry. French Drain Sizing French-drain runoff, gravel void storage, perforated pipe capacity, storage duration, required trench length and limiting drainage area. Septic Tank Size Minimum septic tank size from bedrooms and cited state code-table minimums, with a garbage-disposal step and a 2x daily-flow cross-check. Swale Capacity Vegetated drainage swale runoff, trapezoidal channel capacity, velocity, required depth, freeboard and limiting drainage area. Culvert Capacity Culvert runoff, circular or box barrel Manning capacity, full-flow velocity, required size and limiting drainage area. HDPE Bend Radius HDPE and PE pipe minimum bend radius, required curve length, available deflection, chord length and offset from OD and radius multiplier. Pipe Support Span Pipe hanger or support spacing screen from OD, wall thickness, material stiffness, fluid fill, uniform load, deflection and bending stress. Pipe Pressure Rating Barlow thin-wall pipe pressure rating, required wall thickness, hoop stress, utilization and wall margin from OD, wall, allowable stress and design pressure. Pump NPSH NPSH available, margin and ratio from absolute suction pressure, static head, vapor pressure, line loss and density. Chemical Feed Rate Water-treatment chemical feed rate, metering-pump setting, mL/min, gpd and day-tank runtime from flow, ppm dose, strength and specific gravity.
Mini-split room sizing, furnace BTU, hydronic BTU/GPM, duct size, duct friction loss, duct transitions, CFM/BTU, ACH, static pressure, grille sizing, refrigerant line sizing and charge.
A2L Refrigerant Charge Limit Max allowable A2L refrigerant charge (R-454B, R-32) and minimum room area by floor area and mounting height, per the UL 60335-2-40 / ASHRAE 15 relation — screen an install against the 2025 AIM Act limits. Fan Law Fan affinity laws: new CFM, static pressure and brake power from a speed change, or required RPM for a target airflow. Duct Transition HVAC duct reducer and transition length, taper angle, inlet/outlet velocity, velocity pressure change and sheet-metal blank area from rectangular or round outlet geometry. Air Changes per Hour Required airflow from room volume and target ACH, plus actual air changes per hour from design or measured airflow. Infiltration ACH Natural Blower-door ACH50 to natural infiltration via the LBL-style N factor, with CFM50 and average natural airflow. Makeup Air CFM Exhaust balance for kitchen hoods and other fans: required makeup air with the ~400 CFM residential trigger flagged. Window SHGC Heat Gain Solar gain through glazing: q = SHGC × A × I from the NFRC rating, glass area and incident irradiance, with cooling tons and per-area flux. Duct Fitting Pressure Loss Dynamic loss for any fitting from your C coefficient: velocity pressure ρV²/2, ΔP = C × VP, totaled across identical fittings. HVAC Airflow & BTU Load Sensible BTU/h or kW from airflow and temperature difference, with required CFM, cooling tons and CFM per ton. BTU/GPM Delta T Hydronic BTU/h or kW from liquid flow and Delta T, with required GPM, required Delta T, mass flow and a 500 x GPM x Delta F water-shortcut comparison. Coil Bypass Factor Bypass and contact factor from entering/leaving dry-bulb and apparatus dew point, with the 0.05-0.30 comfort band. Grille Size Size HVAC grilles, registers and diffusers from airflow, target face velocity and free-area ratio. Refrigerant Line Size Screen suction and liquid refrigerant line IDs from capacity, equivalent length, entered refrigerant properties, velocity targets and pressure-drop budgets. Refrigerant Line Charge Estimate added refrigerant charge from line-set length, factory-included length and manufacturer charge rate or liquid-line volume.
Voltage drop, motor amps, grounding, access-control power, transformer kVA, fault current, PV strings, conduit fill, pull tension and wire/raceway checks.
Parallel Conductor Ampacity Total usable ampacity for parallel conductors from user-entered per-conductor ampacity, derating factors, terminal cap and current-sharing allowance. Feeder Conductor Size Two-path conductor check: 125% continuous + noncontinuous at terminations, and corrected ampacity vs load after derating. Short-Circuit Current Transformer secondary short-circuit current and available fault current from kVA, impedance percent, X/R ratio, optional source and downstream impedance. Motor Full-Load Amps Formula motor full-load amps from horsepower or kW, voltage, phase, efficiency and power factor, with design-current and service-factor checks. Motor Inrush Current Locked-rotor amps from the nameplate code letter (NEC 430.7(B) kVA/hp bands), single or three phase, with the times-FLA multiple. Transformer Secondary Conductor NEC 240.21(C) rule paths (10 ft, 25 ft, industrial, outside, primary-protected): required ampacity with the governing rule named — table-free. Conduit Pull Tension Wire or cable pull tension, capstan bend multiplier, sidewall pressure and utilization from route length, friction, bend angle and manufacturer limits.
Pulleys, sprockets, belts, chains, overhung loads, bearings, lead screws.
Pulley Pulley ratio, driven RPM and belt speed from pulley diameters. Sprocket Sprocket ratio, RPM, chain speed and pitch diameters for a chain drive. Sprocket Pitch Diameter Roller-chain sprocket pitch diameter from chain pitch and tooth count, plus chain travel per rev and speed. Belt Length Two-pulley belt length and wrap angle from center distance and diameters. V-Belt Length Solve V-belt pitch length or center distance, plus wrap angle, ratio, RPM and belt speed. Chain Length Roller-chain length in links and mm from sprocket teeth and center distance. Roller Chain Tension Roller-chain tension from chain pitch, driver teeth, RPM and power, with service factor, strand count and allowable tension margin. Overhung Load Overhung shaft load, bearing reactions, load amplification and bending moment from torque, pitch diameter and load position. Timing Belt Timing-belt pitch length, exact/whole belt teeth, selected-belt center distance, pulley pitch diameters, wrap and teeth in mesh. Lead Screw Torque Size lead screw torque, available thrust, linear speed and critical RPM from load, lead, efficiency, screw diameter and support layout. Rack and Pinion Rack travel per pinion revolution, linear speed and force from module, teeth, RPM and torque. Belt Tension Tight-side, slack-side and effective belt tension from power, speed, wrap angle and friction.
Tires, gearing, fleet fuel, fuel surcharge recovery, freight density, axle loads, payload, tongue weight, ballast, PTO power, driveshaft, brakes and chassis.
Tire Size Compare tire diameter, circumference, revs per mile/km and speedometer change from tire sizes. Wheel Offset Compare wheel width, offset, spacer, backspacing, inner clearance and outer poke. Engine RPM Cruise engine RPM from road speed, tire diameter, transmission gear, final drive and transfer ratio. Vehicle Speed Road speed from engine RPM, tire diameter, transmission gear, final drive and transfer ratio. Gear Speed Table Speed in 1st through 6th gear from target RPM, tire diameter, transmission ratios and final drive. Final Drive Ratio Required axle or final-drive ratio from target RPM, road speed, tire diameter and transmission ratio. RPM Drop After-shift RPM, RPM drop and power-band margin from shift RPM and gear-ratio spacing. Torque Converter Slip Converter or clutch slip percentage from measured RPM, road speed, tire diameter and drivetrain ratios. Wheel Torque Wheel torque and tire contact force from engine torque, gear ratios, efficiency and tire radius. Aero Drag Horsepower Aerodynamic drag, rolling resistance and wheel horsepower needed to hold a target road speed. Fleet Fuel Cost Fleet route fuel, idle fuel, daily fuel, period fuel cost and cost per mile from MPG, route distance, vehicles and trips. Fleet Maintenance Cost Maintenance cost per mile from parts, labor, tires and outside repairs, with per-vehicle-month and annualized budgeting views. Trucking Fuel Surcharge Per-mile trucking fuel surcharge, total FSC, linehaul split and diesel recovery margin from entered diesel price, base price, MPG and miles. Freight Density Freight density, pallet cube, dimensional weight and billable-weight screen from handling-unit weight, count and packed dimensions. Truckload Capacity Truckload pallet positions, stack levels, trailer cube, payload margin and limiting factor from trailer and pallet dimensions. Truck Axle Load Static front and rear axle loads, GVWR margin, GAWR margins and remaining payload from scale weights, wheelbase and cargo CG positions. Truck Payload Truck payload used, GVWR margin, front/rear axle loads and extra cargo capacity from ratings, scale weights and load split. Trailer Tongue Weight Trailer tongue weight, tongue percent, axle-group load and load-position shift from empty trailer weight, hitch-to-axle distance and cargo CG locations. Towing Capacity Real towing math from your door-sticker GVWR/GCWR/curb: max trailer, tongue weight and the payload-after-tongue check. Ballast Weight Target ballast, counterweight mass, ballast weight chart, volume, standard weight count and mass-distance moment from load arms and material density. Tractor PTO Horsepower Tractor PTO and implement horsepower from shaft torque/RPM or draft pull/speed, with efficiency, margin, utilization and equivalent PTO torque. Quarter Mile Empirical quarter-mile ET and trap-speed estimate from race weight, engine power and drivetrain efficiency. Flywheel Inertia Flywheel inertia, stored energy, rim speed and gear-reflected equivalent vehicle mass. Stopping Distance Reaction distance, braking distance and total stopping distance from speed, reaction time and deceleration g. Brake Line Pressure Hydraulic brake line pressure from pedal force, pedal ratio, assist multiplier and master cylinder bore. Brake Master Cylinder Bore Required master cylinder bore from target line pressure, pedal force, pedal ratio and assist. Brake Bias Front/rear brake bias from line pressures, piston area, pad friction, rotor radius and tire radius. Brake Torque Disc brake torque, caliper clamp force and tire contact force from pressure, piston area and rotor radius. Brake Heat Stop energy and simple front/rear rotor temperature rise from speed, mass, brake bias and rotor mass. Lateral Acceleration Lateral g, lateral tire force and skidpad lap time from vehicle speed, turn radius and mass. Weight Transfer Longitudinal axle load transfer from mass, static balance, CG height, wheelbase and braking or acceleration g. Roll Center Load Transfer Axle lateral load transfer split into roll-center geometric and elastic components. Tire Contact Patch Tire normal load, contact patch area and approximate patch length from load and pressure. Ackermann Steering Ideal outside steer angle, turn radius and Ackermann percentage from wheelbase, track and steering angles. CV Joint Angle CV axle operating angle from shaft length and vertical or fore-aft offset between joint centers. Compression Ratio Static engine compression ratio from bore, stroke, chamber, piston, deck and gasket volumes. Dynamic Compression Ratio Dynamic engine compression ratio from static geometry, rod length and intake valve closing angle. Piston Speed Mean piston speed from stroke and RPM, plus RPM at a target piston speed. BMEP Brake mean effective pressure from torque, displacement and two-stroke or four-stroke cycle. Engine Airflow CFM Four-stroke engine airflow and mass airflow from displacement, RPM, VE, boost and air density. Exhaust Resonator Quarter-wave side-branch and Helmholtz resonator tuning from frequency, gas temperature, branch/neck size and cavity volume. Fuel Injector Flow Required injector flow rating from power, BSFC, injector count, duty cycle, density and fuel pressure. Valve Spring Rate Valve spring rate, seat load, open load, coil-bind clearance and open stress from wire diameter, coil geometry, installed height and lift. Clutch Torque Capacity Clutch torque capacity, design margin and required clamp force from friction, radius and surface count. Driveshaft RPM Driveshaft RPM, wheel RPM, speed at critical RPM and utilization from road speed, tire diameter and axle ratio. Driveshaft Critical Speed Tubular driveshaft first bending critical speed from length, diameter, wall thickness, modulus and density. Driveline Angle Front and rear U-joint working angles, largest angle and angle difference from transmission, driveshaft and pinion measurements. Suspension Wheel Rate Wheel rate and ride frequency from spring rate, motion ratio, installation angle and sprung corner mass. Corner Weight Total weight, front/rear balance, left/right balance, cross weight and wedge delta from four scale readings.
Va, stall margin, load factor, TAS, turns, wind, descent, range and CG.
Maneuvering Speed Calculate Va from 1g stall speed and positive limit load factor, with load-factor caveats for POH/AFM use. Maneuvering Speed by Category Estimate Va from 1g stall speed using common normal, utility, acrobatic or custom load factors. Limit Load Factor from Va Back-solve implied positive limit load factor from maneuvering speed and 1g stall speed. Stall Speed from Va Infer 1g stall speed from maneuvering speed and positive limit load factor. Corner Speed Calculate simplified positive corner speed from 1g stall speed and limit load factor. Va Weight Adjustment Adjust a published maneuvering speed for operating weight using the square-root weight relation when the POH permits it. Va Weight Table Build a Va-by-weight table and chart from published Va, reference weight and actual weight. Stall Speed Estimate stall speed from aircraft weight, wing area, air density and CLmax using the lift equation. Stall Speed Weight Adjustment Adjust a published stall speed for actual weight using the square-root weight relation. Stall Margin Check available load factor, accelerated stall speed and airspeed margin for a planned g load. Load Factor Find coordinated level-turn load factor from bank angle and the accelerated stall speed from 1g stall speed. Bank Angle from Load Factor Convert load factor to equivalent coordinated level-turn bank angle and accelerated stall speed. Accelerated Stall Speed Calculate accelerated stall speed from 1g stall speed and load factor, with equivalent level-turn bank angle. Turn Radius Coordinated level-turn radius, turn rate and load factor from airspeed and bank angle. Turn Load Factor Calculate coordinated-turn load factor, bank angle and turn rate from true airspeed and turn radius. Standard Rate Turn Bank angle, radius and load factor for a standard-rate or target-rate turn from true airspeed. Density Altitude Estimate pressure altitude, ISA temperature deviation, dry-air density altitude and the 120 ft/C quick check from field elevation, altimeter setting and OAT. True Airspeed Estimate TAS from equivalent or approximate calibrated airspeed, pressure altitude and outside air temperature. Crosswind Component Headwind, tailwind, steady crosswind and gust crosswind components from wind direction, runway heading and speed. Glide Distance Still-air glide distance, descent angle, sink rate and time from altitude, glide ratio and glide speed. Climb Gradient Convert climb rate and ground speed into climb gradient, feet per nautical mile, climb angle and obstacle-height gain. Descent Planning Top-of-descent distance, descent time, actual descent angle and required descent rate for a target path. Aircraft Range & Endurance Endurance, reserve time, usable cruise time and still-air range from fuel quantity, burn rate and ground speed. V-n Diagram Simplified V-n envelope corner speeds from positive/negative stall speeds, limit loads and Vne. Approach Speed Estimate base Vref, gust additive and target approach speed from Vso and a reference factor. Aircraft Weight & Balance Calculate loaded aircraft weight, total moment, CG arm and margin to forward/aft CG limits from station weights and arms. Part 103 Ultralight Screen powered or unpowered ultralight weight, fuel, speed and basic use thresholds against 14 CFR Part 103.1.
Solenoid force, magnet fields, pull force and holding force.
Bolt preload, torque, shear pins, anchor pullout, bolt circles, weld sizing, amperage setup, heat input, duty cycle, groove takeoffs and wire feed.
Bolt Preload & Torque Clamp force from tightening torque and nut factor, with proof-load utilization, target torque and preload scatter. Bolt Circle Coordinate X-Y hole coordinates and spacing on a bolt circle, with a layout render. Fillet Weld Size Effective throat and weld capacity from leg size, length and electrode (AWS/AISC). Weld Throat Fillet weld throat, throat area, capacity and required equal leg from equal/unequal legs, root opening and ASD/LRFD basis. Welding Amperage Starting MIG, TIG, stick and flux-cored amperage range from process, material, thickness and electrode setup. Groove Weld Area Groove weld cross-section area, volume, deposited mass and filler takeoff from joint prep, root opening, bevel angle and weld length. Bolt Shear Strength Ultimate shear capacity of a bolt from grade, diameter and pitch — thread or shank plane, single or double shear. Shear Pin Diameter Required round pin diameter from shear force, allowable stress, safety factor and shear planes. Bolt Pattern Force Shear load per bolt in a circular pattern under a torsional moment plus direct shear. Thread Pitch Diameter Pitch (effective) diameter of a 60° thread by the three-wire method, plus the best wire size. Thread Engagement Check engaged thread length against internal and external thread stripping for metric, UNC and UNF threads. Torque to Tension Convert tightening torque to bolt tension, or target preload to required torque, with nut factor K. Bolt Elongation Elastic bolt stretch, stress and strain from preload, stressed length, area and modulus. Bolt Bearing Stress Average bolt or pin bearing stress from projected area d*t, load per fastener and allowable stress. Epoxy Anchor Pullout Formula-only adhesive anchor tension screen from entered embedment, bond stress, steel stress and safety factor. Weld Group Rectangular weld-group stress and required fillet leg under eccentric in-plane loading.
K-factor, bend allowance/deduction, box/tray blanks, cone patterns, square-to-round transitions, powder coating, blank length and tonnage.
Bend Allowance Bend allowance, deduction and setback from angle, radius, thickness and K-factor. Bend Deduction Flat blank length, bend deduction and normalized bend deduction chart for press-brake layout. Cone Flat Pattern Conical frustum flat pattern radii, sector angle, slant height, arc lengths and blank area from diameters and height. Square to Round Transition Square or rectangular-to-round transition layout worksheet with station true lengths, perimeter mismatch, blank area, seam allowance and shell mass. Press Brake Tonnage Air-bending press force from thickness, bend length, V-die opening and material strength. Punching Force Punch tonnage F = perimeter × t × shear strength for round, rectangular or custom punches, plus stripping force. V-Die Opening Air-bending die selection: V = m×t (rule of 8), floated inside radius ≈ %×V, minimum flange 0.77×V, V/t safety check.
Deck joist and beam spans, wood spans, lintels, shelf sag, rafters, stairs, trim miters, deck and rebar takeoffs, rigging specs/tension and deflection.
Section Modulus Area moment I, section modulus S = I/c, area and neutral axis for a rectangle, round, tube, I-beam, channel, tee or angle. Block Shear Capacity AISC 360 block shear rupture (Eq. J4-5): Rn = 0.6·Fu·Anv + Ubs·Fu·Ant capped by gross-section yield, with LRFD φRn and ASD Rn/Ω from your shear and tension areas. Shaft Torsion Circular-shaft torsion stress, angle of twist, polar moment J and torque capacity. Shaft Deflection Bending deflection, stress and I for a round shaft as a beam (simply supported or cantilever). Square Tube Deflection Deflection, stress and I of a square/rectangular HSS tube used as a beam. Beam Deflection General beam deflection, bending moment and stress from I and S for common point and uniform load cases. Deck Beam Span Preliminary deck beam span and post-spacing screen from built-up plies, tributary deck width, loads and entered E, Fb and Fv values. Concrete Slab Rectangular slab concrete volume, cubic yards, bags, ready-mix truckloads, weight and entered-price cost from dimensions, count and waste. Rebar Spacing Rectangular slab, wall or footing rebar layout takeoff: bar count, actual spacing, total length, stock sticks and estimated weight. Trim Molding Baseboard, crown, chair rail or casing linear feet, stock pieces, waste, leftover and material cost from room dimensions and openings. Wire Rope Stretch Wire rope or standing-rigging elastic stretch, constructional stretch, total stretch, stiffness and metallic area. Sling Angle Load Multi-leg sling or bridle angle tension, angle factor, required per-leg WLL and utilization from load, loaded legs and sling angle. Rigging Center of Gravity Two-pick rigging center-of-gravity load share, left/right pick loads, sling-leg tension, WLL utilization and limiting total load. Outrigger Pad Size Crane pad/mat bearing area from outrigger reaction ÷ allowable ground pressure, plus the GBP check of the pad you carry. LVL Beam Preliminary LVL beam sizing from span, plies, depth, uniform line loads and product design values, with bending, shear and deflection checks.
Charts & reference tables
All referencePrintable, cited standards data — the tables behind the calculators. Tap-drill, drill & thread sizes, material densities, hardness conversion, pipe schedules and more.
Spring wire material properties Spring stress correction calculator Helical spring calculator Spring solid height calculator Mean coil diameter calculator Initial tension extension spring calculator Spring shear stress formula Torsion spring deflection angle Active coils formula Wire diameter for load Tap drill chart Drill size chart Thread pitch chart Decimal to fraction chart Cutting speed chart (SFM by material) Chip load chart Keyway size chart Keyway dimensions by shaft size Dovetail measurement over pins Deep-hole peck cycle calculator Countersink diameter depth Spot drill depth by chamfer diameter Chip load by thread pitch Thread pitch calculator Thread milling passes Material density chart Material weight calculator Steel weight calculator Stainless steel weight calculator Bar weight calculator Aluminum weight calculator Round bar weight calculator Steel round bar weight calculator Steel plate weight calculator Steel tube weight calculator Square tube weight calculator 304 stainless weight calculator 316 stainless weight calculator Board feet chart Board foot calculator Lumber board foot calculator Lumber cost calculator Wood weight calculator Timber weight calculator Plywood calculator Plywood material calculator 4x8 plywood calculator Plywood cut calculator Plywood cut list calculator Kerf calculator Wood movement calculator Dovetail layout calculator Dovetail angle calculator Mortise tenon calculator Tenon size calculator Dado calculator Drawer box calculator Dust collection CFM calculator Dust collector sizing calculator Paint coverage calculator Woodworking calculators Woodworking calculator Shelf deflection calculator Steel weight formula Aluminum weight formula Stainless steel weight formula Round bar weight formula Plate weight formula Pipe weight formula Square tube weight formula Rectangular tube weight formula Hardness conversion chart Steel pipe schedule chart Pipe fitting takeout chart ISO 286 hole & shaft fit table GD&T symbols chart Geo tolerance symbols Pipe pressure drop worksheet Pump horsepower chart Water pipe pressure loss Pump head loss plumbing Pump NPSH available calculator Hydraulic cylinder speed worksheet Hydraulic reservoir size by GPM Hydraulic hose size worksheet Accumulator size worksheet PEX pipe size worksheet Expansion tank size worksheet Hydronic expansion tank Pipe slope formula Drainage pipe slope Drain pipe slope Water hammer pressure worksheet Roof drain GPM calculator Pipe miter calculator Pump flow GPM formula Motor torque displacement formula Duct size worksheet Duct size by CFM Line set size by tonnage Refrigerant line size by tonnage Suction line size calculator Liquid line size calculator Duct friction loss worksheet Total external static pressure Available static pressure Static pressure worksheet Furnace BTU by square footage Flex duct CFM capacity chart Plenum sizing velocity calculator Manual D friction rate calculator Return air grille size calculator Equivalent round duct Transformer kVA chart Conduit fill chart Conduit fill by wire size Voltage drop from transformer kVA Voltage drop by wire size NEC voltage drop calculator Solar PV wire size Transformer impedance fault calculator Parallel conductor ampacity worksheet Motor full-load current by HP Ground wire size by breaker NEC box fill calculator Conduit offset formula Involute gear formula Involute gear Bevel gear pitch angle calculator Bolt torque spec chart Wrench size chart Weld symbol reference Bolt preload formula Bolt preload calculation M10 bolt preload Bolt clamp force calculator Torque tension equation Bolt pretension calculation Bolt group force calculator Bolt pattern shear calculator Thread wire measurement calculator Overhung load formula Rack and pinion force calculator Rack and pinion ratio calculator Belt calculator Ballast weight chart Sheet metal gauge chart K-factor calculator K-factor for copper sheet metal Bend allowance K-factor Sheet metal K-factor chart Aluminum K-factor Brass K-factor Bend allowance chart Bend allowance formula Minimum flange length chart Relief notch size calculator Square tube deflection chart Square tube deflection formula Shaft torsion formula Miter angle calculator Deck calculator Deck material calculator Fence calculator Fence material calculator Wood fence calculator Rafter length chart Rafter length by pitch Stair stringer chart Stair rise/run calculator I-beam moment of inertia calculator Lintel size chart Header size calculator Deck footing size by load Joist span by species Deck joist span by spacing Beam point load deflection calculator Euler column buckling load calculator Simply supported shaft deflection Shaft stress calculator Miter saw bevel angle Rectangular section modulus formula Round section modulus formula Tube section modulus formula I-beam section modulus formula
Guides
All guidesThe formulas and standards behind the tools, explained.
Spring rate formula explained The Wahl correction factor How to calculate chip load SFM to RPM conversion What is the K-factor in sheet metal? Bend allowance vs bend deduction What is true position in GD&T? How to read GD&T symbols Metal weight formula Bolt preload explained Thread engagement explained How to size a hydraulic cylinder Hydraulic cylinder force formula How to calculate gear ratio Gear module vs diametral pitch Involute gear geometry How to calculate belt length What is overhung load? What is section modulus? How to size a mini split The voltage drop formula, explained How to calculate compression ratio What is maneuvering speed (Va)? How solenoid force works How to calculate board feet Pump NPSH, explained Deflection limits: L/360, L/240, L/180 Shaft torsion & angle of twist Square tube deflection, explained Keyway sizes, explained Sprocket pitch diameter, explained Thread classes, explained Three-wire thread measurement, explained How to measure gear teeth, explained How to measure a compression spring, explained How to measure a taper, explained How to lay out a pipe bend, explained How to measure a dovetail, explained How to size an LVL beam, explained Fillet weld size, explained How to read a bearing number, explained Rack and pinion travel and force, explained MMC and bonus tolerance HVAC static pressure, explained Bearing L10 life, explained Wood movement, explained Welding heat input, explained Planetary gear ratios, explained Countersink depth, explained How to design a compression spring Timing belt length, explained Quench and temper, explained Solid height and coil bind, explained ISO limits and fits, explained Pipe miter cut, explained How to calculate bolt shear strength How to calculate block shear How to calculate interference fit pressure How to calculate gear mesh forces Thread pitch and TPI, explained How to calculate cable pulling tension
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