HP to in-lbs Torque Calculator
Convert horsepower and RPM into torque in inch-pounds.
HP to in-lbs Torque Calculator
RESULT
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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.
Quick answer: Torque (in-lb) = (HP × 5252 ÷ RPM) × 12. A 5 HP motor at 1,750 RPM makes about 180 in-lb.
HP to in-lbs Torque Formula
Formula
Torque (in-lb) = (HP × 5252 ÷ RPM) × 12
First find lb-ft via the 5252 rule, then multiply by 12.
How to Use This Calculator
- Enter horsepower.
- Enter RPM.
- Read torque in inch-pounds (and lb-ft).
Worked Example
Worked Example
lb-ft = (5 × 5252) ÷ 1750 = 15 lb-ft
in-lb = 15 × 12 = 180 in-lb
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.