Calculator
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.
Formulas
i = n₁ / n₂
n₂ = n₁ / i
M₂ = M₁ × i × η
P₂ = P₁ × η
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]
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.
Matching Products & Guides
Product
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Worm and bevel gearboxes — find the right model directly using the calculated gear ratio.
ProductDrive Technology Range
Gearboxes, motors, couplings, and freewheels for complete drive solutions from a single source.
Pillar PageDrive Technology Guide
Selection guides, comparisons, and formulas for gearboxes, motors, and couplings.
ComparisonWorm vs. Planetary Gearbox
Efficiency, ratio, and cost in direct comparison — for the right gearbox selection.
CalculatorTorque Calculator
Calculate torque, power, and speed online — free and without registration.