HP to in-lbs Torque Calculator
Convert horsepower and RPM into torque in inch-pounds.
This calculator finds torque in inch-pounds from horsepower and RPM — useful for small motors and gearmotors where torque is rated in inch-pounds rather than foot-pounds.
HP to in-lbs Torque Formula
How to Use This Calculator
- Enter horsepower.
- Enter RPM.
- Read torque in inch-pounds (and lb-ft).
Worked Example
When Inch-Pounds Are Used
Inch-pounds are the natural torque unit for small motors, gearmotors, servos, and precision mechanisms where foot-pounds would be awkwardly small fractions. Power-tool makers, fractional-horsepower motor manufacturers, and fastener specs for delicate assemblies all quote torque in in-lb. Since there are 12 inches in a foot, in-lb is simply lb-ft × 12.
HP to Inch-Pounds at 1,750 RPM
| Horsepower | Torque (lb-ft) | Torque (in-lb) |
|---|---|---|
| 0.5 | 1.5 | 18 |
| 1 | 3.0 | 36 |
| 5 | 15.0 | 180 |
| 10 | 30.0 | 360 |
Torque depends on RPM, so the same horsepower yields more torque at lower speeds — a key reason gear reduction is used to boost torque in compact drives.
Frequently Asked Questions
First find torque in lb-ft using (HP × 5252 ÷ RPM), then multiply by 12 to get inch-pounds. You need the RPM.
Torque depends on the speed at which power is delivered. The same horsepower produces different torque at different RPM.
Twelve. One foot-pound of torque equals 12 inch-pounds.
For small motors, gearmotors, and fasteners where foot-pounds would be awkwardly small numbers.
Convert in-lb to lb-ft (divide by 12), then use HP = (lb-ft × RPM) ÷ 5252.