Motor Torque Calculator
Calculate electric motor shaft torque from rated power and speed using T = P × 9549 / n.
How to Use the Motor Torque Calculator
- Enter the motor rated power from the nameplate in kW.
- Enter the rated speed in RPM.
- Click Calculate to get the full-load shaft torque in N·m.
Casos de Uso
- •Sizing couplings and gearboxes for electric motors.
- •Checking shaft and key strength under full-load torque.
- •Comparing motor options for conveyor and pump drives.
Fórmula
T = P × 9549 / n, where T is torque (N·m), P is power (kW), n is speed (RPM). Derived from T = P / ω and ω = 2πn/60.
Perguntas Frequentes
Why use 9549 in the formula?
9549 = 60000 / (2π) ≈ 9549. It converts kW and RPM directly to N·m without separate unit conversions.
Does this give full-load torque?
Yes, when you enter rated power and rated speed from the motor nameplate, the result is the full-load (rated) torque. Starting torque is typically 1.5–2.5× higher.
Is this calculator free?
Yes, all OhMyCalc calculators are completely free to use.