🐎 Horsepower & Torque Calculator
Convert between horsepower and torque at any engine speed — enter two of the three and get the third, plus the metric kW and N·m equivalents.
Horsepower
285.6 hp
213 kW
Power in kW
213 kW
Horsepower = torque (lb-ft) × RPM ÷ 5252 — the constant 5252 is where the torque and power curves always cross on a dyno. 1 hp = 0.7457 kW; 1 lb-ft = 1.356 N·m. 🔒 In your browser.
How the horsepower & torque calculator works
Power is torque times rotational speed, and in the traditional units that relationship is horsepower = torque (lb-ft) × RPM ÷ 5252. The constant 5252 comes from 33,000 ÷ 2π (one horsepower is 33,000 ft-lb per minute). Rearranged, torque = horsepower × 5252 ÷ RPM. The tool also converts to kilowatts and newton-metres.
A consequence of the formula: horsepower and torque are always numerically equal at 5252 RPM — which is why dyno graphs of the two curves always cross at that point. Below 5252 RPM torque is the larger number; above it, horsepower is.
Frequently asked questions
How do I convert torque to horsepower?
Horsepower = torque (lb-ft) × RPM ÷ 5252. So 300 lb-ft at 5,000 RPM is 300 × 5000 ÷ 5252 ≈ 286 hp. The tool converts either direction and adds kW and N·m.
Why is the number 5252 used?
One horsepower is defined as 33,000 foot-pounds of work per minute. Converting rotational torque and RPM into that unit introduces a factor of 2π, and 33,000 ÷ 2π ≈ 5252 — the constant in the horsepower formula.
Why do horsepower and torque cross at 5252 RPM?
Because horsepower = torque × RPM ÷ 5252. At exactly 5252 RPM the RPM ÷ 5252 term equals 1, so horsepower equals torque numerically — the two dyno curves always intersect there.
What is the difference between horsepower and torque?
Torque is the twisting force the engine makes; horsepower is the rate at which it does work — torque combined with how fast the engine spins. Torque gets you moving; horsepower (torque sustained at high RPM) determines top-end performance.
How do I convert horsepower to kilowatts?
Multiply by 0.7457 — 1 hp = 0.7457 kW. So 250 hp is about 186 kW. The tool shows the kW value automatically.