Horsepower Calculator

Torque and RPM — the standard formula behind every dyno chart.

lb-ft

5,252 is the RPM at which torque (lb-ft) and horsepower numerically cross — above that RPM, horsepower exceeds torque; below it, torque is the bigger number.

Horsepower
304.6 HP
In kilowatts
227.2 kW

HP = (Torque × RPM) ÷ 5,252 — the standard relationship between rotational force (torque) and the rate it's applied (RPM) that together define mechanical power.

A worked example

400 lb-ft of torque at 4,000 RPM works out to about 304.6 horsepower.

Frequently asked questions

Why do torque and horsepower curves cross at exactly 5,252 RPM?

It's simply where the math of the formula HP = (Torque × RPM) ÷ 5,252 produces equal numbers for both — at 5,252 RPM the horsepower figure always equals the torque figure, regardless of the engine, which is why dyno charts always show the two curves crossing at that exact RPM.

Why do some cars feel quicker despite having less horsepower?

Torque delivered low in the RPM range produces stronger immediate acceleration, especially from a stop — a high-torque, lower-horsepower engine can feel punchier in everyday driving than a high-revving, high-horsepower one that needs RPM to make its power.