Power Transmission Calculators
Lay out belt, chain, shaft and linear drives: pulley and sprocket ratios and speeds, chain pull, overhung shaft load and bearing reactions, torque-power-RPM conversion, lead screw torque and critical speed, V-belt and timing-belt length, belt tension from the capstan equation, roller-chain length, bearing equivalent load and L10 life, plus rack-and-pinion travel and force.
Pulley
Pulley ratio, driven RPM and belt speed from pulley diameters.
Sprocket
Sprocket ratio, RPM, chain speed and pitch diameters for a chain drive.
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.
Chain Pull
Roller-chain effective pull, design pull, pitch-line speed and sprocket torque from power and RPM.
Overhung Load
Overhung shaft load, bearing reactions, load amplification and bending moment from torque, pitch diameter and load position.
Bearing Life (L10)
Basic L10 rating life in revolutions and hours from load, speed and rating.
Bearing Load
Equivalent dynamic/static bearing load from radial and axial loads plus catalog X/Y factors.
Timing Belt
Pitch length, length in teeth and pulley pitch diameters for a synchronous (toothed) belt drive.
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.
Spline Torque Capacity
First-pass spline torque capacity from flank pressure, pitch diameter and engagement length.
Flywheel Energy
Stored rotational energy, inertia and rim speed for a disk, ring or rim flywheel.
Torque Power RPM
Solve shaft power, torque or RPM from P = T x omega in kW/hp and N*m/lbf*ft.
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These calculators size a complete mechanical drive rather than echo a single textbook formula. The pulley ratio calculator returns the speed ratio i = D₂/D₁, the driven RPM and the rim speed v = π·D·n that both sheaves share without slip, so you can check a reduction before cutting a single bracket. Pair it with the belt length and wrap angle calculator to fix the centre distance, then verify the drive will actually grip: the belt tension calculator applies the capstan equation T₁/T₂ = e^(μθ) to split effective tension into tight- and slack-side strands and warn when low wrap invites slip.
For shaft sizing and motor checks, the torque power RPM calculator solves P = T·ω in either direction, so kW/hp, N·m/lbf·ft and rpm stay consistent before you add efficiency or service factor. The overhung load calculator converts torque, pitch diameter, drive factor, bearing span and load position into radial bearing reactions, load amplification and peak bending moment for shaft sizing; the guide on what overhung load is explains why the nearest bearing can carry more than the applied belt, chain or gear force. For linear axes, the lead screw torque calculator converts axial load, lead and screw efficiency into required motor torque, then checks available thrust, travel speed, lead angle and critical RPM from screw root diameter and bearing support. The rack and pinion calculator covers the alternate rotary-to-linear layout with travel per revolution and push force from module, teeth, RPM and torque.
For chain drives, the chain pull calculator uses F = P/v to convert power and pitch-line speed into design chain pull, while the sprocket and roller-chain length tools work in whole pitches and pitch diameters PD = p/sin(180°/N). The bearing load calculator combines radial and axial load into equivalent dynamic/static catalog loads before the bearing L10 calculator converts C/P into rating life. Every page shows its governing relation and the standard behind it.
It's built for machinists, kart and machine builders, and design engineers who want the real drive parameters — ratio, belt speed, tension, chain pitch, torque, bearing load, thrust and power — not a shallow widget. New to the belt geometry? The guide on how to calculate belt length walks through the derivation.