Gear Ratio Calculator — Speed, Torque & RPM | Engineering Calc Pro

⚙ Gear Ratio Calculator

Speed, torque & RPM for gear pairs and gear trains

Results

Gear Ratio
—
: 1
Output Speed
—
RPM
Output Torque
—
Nm
Power Loss
—
%

Formula Reference

Gear Ratio (GR) = N₂ / N₁ = ω₁ / ω₂

Output RPM = Input RPM / GR

Output Torque = Input Torque × GR × Efficiency

📝 Worked Example

A motor at 1800 RPM / 50 Nm drives a 20-tooth pinion meshing with a 60-tooth gear at 97% efficiency.

InputValue
Driver teeth20
Driven teeth60
Input RPM1800
Input Torque50 Nm

GR = 60/20 = 3 : 1

Output RPM = 1800/3 = 600 RPM

Output Torque = 50 × 3 × 0.97 = 145.5 Nm

Result: GR = 3:1  |  600 RPM  |  145.5 Nm