Motor Torque Calculator

Calculate the rotational force (Torque) produced by an electric motor or engine.

Motor Power (Horsepower - HP)

Rotational Speed (RPM)

Generated Torque

0 lb-ft

The Relationship Between Torque, RPM, and HP

In mechanical engineering, Torque is a measure of the rotational force applied to a shaft, while Horsepower (HP) measures the rate at which work is done over time. They are mathematically locked together by the rotational speed (RPM) using the famous constant 5252.

Standard US Torque Equation: $$ T (lb-ft) = \frac{HP \times 5252}{RPM} $$

The constant 5252 is derived from dividing 33,000 (foot-pounds of work per minute in 1 HP) by $2\pi$ (one revolution).

Unit Conversions

If you are designing equipment for the international market, you must convert Pound-Feet to Newton-Meters (Nm):

1 lb-ft = 1.3558179 Nm
1 Nm = 0.7375621 lb-ft