Gear Ratio Calculator
Gear ratio, output speed and output torque from driver and driven gear teeth.
Inputs
teeth
teeth
rpm
N·m
%
Results
- Gear ratio
- 3 : 1
- Output speed
- 483.3 rpm
- Output torque
- 29.4 N·m
Formula
Ratio = Driven teeth ÷ Driver teeth
Output rpm = Input rpm ÷ Ratio
Output torque = Input torque × Ratio × efficiency
Assumptions & limits
- Single gear pair; for gear trains multiply the stage ratios.
Worked example
36 ÷ 12 = 3:1 → 483.3 rpm, 29.4 N·m.