Motor Torque Calculator

Calculate motor torque for various motor types

Motor Torque Calculator

Compliant with IEC 60034 Standards

Results:

Torque (Nm): 0.00

Torque (lb-ft): 0.00

How to Use the Calculator

Motor Torque Calculation

  1. Enter the motor's Power in Kilowatts (kW).
  2. Input the Rotational Speed in Revolutions Per Minute (RPM).
  3. Provide the motor's Efficiency (a value between 0 and 1, e.g., 0.85 for 85% efficiency).
  4. Click 'Calculate' to get the torque in Newton-meters (Nm) and pound-feet (lb-ft).

Motor Torque Fundamentals

Torque Definition

Torque is the rotational equivalent of linear force. It is a measure of the force that causes an object to rotate about an axis. In motors, torque is the twisting force that the motor produces to turn a load.

Factors Affecting Torque

  • Power (kW): The rate at which work is done. Higher power generally means higher torque for a given RPM.
  • Rotational Speed (RPM): The number of revolutions per minute. For a given power, higher RPM means lower torque.
  • Efficiency: The ratio of output power to input power. Motor losses reduce the effective power available for torque production.

Key Formulas:

Torque (Nm) = (9550 × Power (kW) × Efficiency) / RPM

Torque (lb-ft) = Torque (Nm) × 0.737562

Calculation Formulas

Torque in Newton-meters (Nm):
TNm = (9550 × PkW × η) / N

Torque in Pound-feet (lb-ft):
Tlb-ft = TNm × 0.737562

Where: PkW = Power in kW, η = Efficiency, N = RPM

Example Calculation

Motor Parameters:

Power (kW): 7.5 kW

RPM: 1450 RPM

Efficiency: 0.88

TNm = (9550 × 7.5 × 0.88) / 1450 = 43.5 Nm

Tlb-ft = 43.5 × 0.737562 = 32.09 lb-ft

Torque = 43.50 Nm | Torque = 32.09 lb-ft

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