Horsepower Calculator
Convert torque and RPM into horsepower, or work backwards.
How this calculator works
HP = torque (lb-ft) × RPM ÷ 5252
The constant 5252 is where the horsepower and torque curves always cross on a dyno chart — it comes from 33,000 ft-lb per minute divided by 2π. If your curves cross anywhere else, the plot is wrong.
Worked example
With torque 300 , engine speed 5000 , this calculator returns 285.61 .
Frequently asked questions
What is the difference between torque and horsepower?
Torque is rotational force; horsepower is the rate at which that force does work. Torque tells you how hard the engine pulls, horsepower how fast it can keep doing it.
Why do torque and horsepower cross at 5252 RPM?
It falls out of the formula. Horsepower is torque times RPM divided by 5252, so at exactly 5252 RPM the two are numerically equal. Every correct dyno chart shows the curves crossing there.
How do I convert horsepower to kilowatts?
Multiply by 0.7457. Three hundred horsepower is about 224 kW. Metric horsepower, used in European specifications, is slightly different at 0.7355 kW.
Does more torque mean faster acceleration?
At the wheels, yes — but gearing multiplies torque, so a high-revving engine with modest torque can out-accelerate a low-revving one. What matters is area under the power curve across the usable rev range.