Free Gear Ratio Calculator
Calculate gear ratio, output speed, and output torque for a simple gear pair.
Gear Ratio
3.000
Gear Ratio vs Driver Gear Teeth (N1)
Gear Ratio Fundamentals
Gears trade speed for torque (or vice versa) while transmitting rotational power.
Formulas
Gear Ratio = N2 / N1 (driven teeth / driver teeth)
Output Speed = Input Speed / Gear Ratio
Output Torque = Input Torque x Gear Ratio (assuming no losses)
A ratio greater than 1 is a speed reduction (torque multiplication). A ratio less than 1 is a speed increase (torque reduction).
Example Calculation
A 20-tooth driver meshing with a 60-tooth driven gear, input 1800 RPM at 50 N-m.
- 01Gear ratio = 60 / 20 = 3.0 (speed reduction)
- 02Output speed = 1800 / 3.0 = 600 RPM
- 03Output torque = 50 x 3.0 = 150 N-m (ideal)
- 04Actual torque is slightly less due to mesh efficiency (typically 95-99% per stage).
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