Understanding the Brake Horsepower Calculator
Brake horsepower (bhp) measures an engine’s power output at the crankshaft, before losses from the transmission and accessories. This calculator estimates bhp from performance inputs, giving a standard figure for comparing engines independent of drivetrain.
What “brake” means here
The term comes from the brake-style device historically used to measure engine output on a test bench. Brake horsepower reflects the engine’s power at the crank, which is why it is typically higher than the wheel horsepower you would measure on a chassis dyno, where drivetrain losses reduce the figure that reaches the road.
Comparing figures fairly
When comparing vehicles, make sure you are comparing like with like — crank bhp to crank bhp, or wheel to wheel. Manufacturers usually quote crank figures. Knowing the distinction prevents the common mistake of comparing a manufacturer’s bhp rating directly against a dyno’s wheel-horsepower reading.
Tips & things to know
- •Brake horsepower is measured at the crank, not the wheels.
- •Wheel horsepower is lower due to drivetrain losses.
- •Compare crank-to-crank or wheel-to-wheel figures only.