Horsepower Calculator

Turn torque and rpm into horsepower and kilowatts, and find the torque needed for a target power.

Horsepower calculator

Torque (N m)

Engine speed (rpm)

Target power (hp)

Power in horsepower: —

Power in kilowatts: —

Torque for the target power: —

Target torque in pound-feet: —

—

Horsepower is torque times rpm divided by 7127 when torque is in newton metres, or divided by 5252 when torque is in pound-feet.

Common questions about the free online horsepower calculator.

Multiply the torque in newton metres by the rpm and divide by 7127. With 300 N m at 3000 rpm the result is about 126 horsepower.

With torque in pound-feet, horsepower is torque times rpm divided by 5252, the constant used for imperial dynamometer figures.

Multiply horsepower by 0.7457. One horsepower is 745.7 watts, so 200 horsepower is about 149 kilowatts.

Multiply the target horsepower by 7127 and divide by the rpm, which gives the torque in newton metres at that speed.

At a fixed torque the engine does more work per minute as it turns faster, so power rises in direct proportion to speed.

They measure the same quantity in different units. One mechanical horsepower equals 0.7457 kilowatts exactly at this precision.

Yes. Enter the motor torque in newton metres and its rated speed in rpm, and the calculator returns horsepower and kilowatts.

No. The power figures are calculated locally in your browser, so nothing you enter is sent to a server or stored.

Yes. It is free, unlimited and needs no account, so you can compare as many torque and power figures as you like.

Last updated: October 10, 2026