Machining Calculators
Dial in speeds, feeds, setup and manufacturing estimates: SFM↔RPM, chip load, CNC feed rates, milling, turning and drilling power, drilling feed/time, theoretical surface finish, tap-drill and thread sizing, injection molding shot size and clamp force, tapping and thread-mill feeds, sine-bar angles, ball-nose stepover, countersink depth and drill-point allowance — backed by cutting-speed and drill-size charts.
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.
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.
Milling Horsepower
Milling material removal rate, cutting power, spindle horsepower, torque and chip load from cut engagement and feed.
Turning Horsepower
Turning material removal rate, cutting power, spindle horsepower, torque and cutting force from speed, feed and depth.
Drilling Horsepower
Drilling material removal rate, cutting power, spindle horsepower and torque from drill diameter, RPM, feed and kc.
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.
Surface Finish
Theoretical turning Ra & Rz from feed and nose radius — or the max feed for a target finish.
Surface Finish Ra/Rz Converter
Approximate conversion between Ra, Rz, RMS and ISO N roughness grade.
Tapping Feed Rate
Tapping feed rate Vf = spindle RPM × thread pitch; the feed per rev equals the pitch.
Drilling Feed Rate
Drilling feed rate, point allowance, cycle time, cutting speed and material removal rate.
Thread Mill Feed
Compensate thread-mill feed for helical interpolation — tool-centre from cutting-edge feed.
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.
Countersink Depth
Plunge depth and chamfer width of a conical countersink from angle, rim and hole diameter.
Drill Point Length
Drill tip allowance and total blind-hole depth from diameter, point angle and full-diameter depth.
Dovetail
Over-pin / between-pin measurement for inspecting a male or female dovetail slide.
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This cluster runs the actual shop-floor and manufacturing math rather than a generic physics widget. The CNC speeds and feeds calculator takes spindle speed from cutting speed and tool diameter, n = Vc/(π·D), then derives feed rate from chip load and flute count, Vf = fz·Z·n, and reports the material removal rate Q = aₚ·aₑ·Vf — the numbers that decide tool life, feed time and spindle load. If you only need to convert a target surface speed, the SFM-to-RPM calculator handles RPM = (SFM·12)/(π·D) for both turning (work diameter) and milling or drilling (tool diameter).
It is built for machinists, CNC programmers, estimators and manufacturing engineers who want a defensible starting point, not a guess. Each tool shows its formula, and feed work is backed by the cutting-speed chart by material so your Vc is grounded in published data. For milling, the chip load calculator solves fz ↔ Vf in either direction, and the milling horsepower calculator carries width of cut, depth of cut, feed rate and specific cutting force into MRR, spindle power and torque. For lathe work, the turning horsepower calculator uses work diameter, cutting speed, feed per revolution, depth of cut and kc to estimate turning MRR, spindle power, torque and cutting force. For holemaking, the drilling feed rate calculator turns RPM and feed per revolution into cutting feed, drill-point allowance, cycle time and material removal rate, while the drilling horsepower calculator checks drill-area MRR, spindle power and torque.
After the process numbers are believable, the machining time calculator converts cutting length, approach, overtravel, passes and feed rate into feed time, cycle time, batch time and parts per hour. Then the machining cost calculator converts material, scrap, setup time, cycle time, shop rate, tooling, secondary work and markup into direct cost, quoted price each and batch total. For molded plastic parts, the injection molding shot size calculator checks part weight, runner weight, cavity count, machine shot utilization and projected-area clamp force before a press is selected. Unlike tool-vendor wizards that gate a quote, MachineCalcs runs in metric and imperial and pairs speeds-and-feeds with setup math — tap drill, sine bar, ball-nose stepover, countersink depth and drill point length for blind-hole allowances.