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Gear Ratio Calculator

Gear ratio, output speed, and output torque — including efficiency factor.

Enter Input Values

Enter the known values — the rest will be calculated automatically.

min⁻¹
Nm
%

Formulas

i = n₁ / n₂
n₂ = n₁ / i
M₂ = M₁ × i × η
P₂ = P₁ × η
i = Gear ratio [-]
n₁/n₂ = Input/output speed [min⁻¹]
M₁/M₂ = Input/output torque [Nm]
η = Efficiency [0–1]

Typical Efficiencies

Spur gearbox97–99%
Planetary gearbox95–98%
Bevel gearbox95–98%
Worm gearbox40–90%

Note: Efficiency η is entered as a percentage value (e.g. 95 for 95%). For multi-stage gearboxes, individual stage efficiencies are multiplied together.

Notice: The calculation tools provided are intended for initial orientation only and do not replace binding engineering design by qualified specialists. All results must be verified by appropriate engineering calculations before use in safety-critical applications. Technische Antriebselemente GmbH accepts no liability for damages arising from the use of the calculation results.

+49 [40] 5388921-11 sales@tea-hamburg.de