Horsepower & Torque Calculator
Solve for horsepower, torque, or RPM using HP = torque × RPM ÷ 5252.
Horsepower
366.5 hp
Horsepower equals torque times RPM divided by 5252. That's why every engine's HP and torque curves cross right at 5252 rpm.
How it works
Horsepower, torque, and engine speed are locked together by one formula: horsepower equals torque in pound-feet times RPM, divided by 5252. Know any two and the third falls out.
That 5252 isn't arbitrary — it's 33,000 divided by 2 pi, the number that converts a twisting force spinning at some RPM into James Watt's unit of horsepower. It's the same constant behind every dyno chart.
Pick which value you want on the calculator, enter the other two, and it does the algebra. Solving for horsepower uses torque times RPM over 5252; solving for torque or RPM just rearranges the same equation. A curious quirk: torque and horsepower curves always cross at exactly 5252 RPM.
Frequently asked questions
What's the difference between horsepower and torque?
Torque is the twisting force the engine makes right now; horsepower is how much of that force it can deliver over time. Torque gets you moving, horsepower keeps you accelerating at speed.
Why does everything hinge on 5252?
It comes from the definition of one horsepower — 33,000 foot-pounds of work per minute — divided by 2 pi radians per revolution. That's why the torque and HP lines on a dyno graph always intersect at 5252 RPM.
Can I use metric torque figures?
This tool expects torque in pound-feet and gives horsepower in mechanical HP. If you have newton-meters, divide by about 1.356 to get pound-feet first, then enter that.