Transportation

Engine Horsepower Calculator

Use OmniCalc's engine horsepower calculator to estimate engine output from torque and RPM.

Engine horsepower calculator

Estimate crank and wheel horsepower from torque and RPM.

Use this calculator to estimate engine horsepower from torque and RPM, then apply an optional drivetrain-loss percentage to compare crank horsepower with approximate wheel horsepower.

This page is intentionally different from the existing Horsepower Calculator. That page converts power units; this one estimates engine output from torque and RPM.

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Why this result matters

What this calculator helps you answer

A more specialized engine-output estimator that complements the existing horsepower unit converter by turning torque and RPM into crank and wheel horsepower with an optional drivetrain-loss assumption. Use the tool above to enter a few clear inputs and get a practical answer you can use right away.

This engine horsepower calculator helps drivers, tuners, equipment shoppers, and performance enthusiasts estimate horsepower from torque and RPM without doing the formula manually. It also includes an optional drivetrain-loss setting so you can compare rough crank horsepower with approximate wheel horsepower for more practical interpretation.

Formula and method

How the calculation works

The calculator converts torque to lb-ft when needed, applies horsepower = torque × RPM ÷ 5252, then optionally estimates wheel horsepower after drivetrain loss and converts the result to kilowatts.

Example

Example engine horsepower estimate

If an engine makes 300 lb-ft at 6,000 RPM, the calculator estimates about 342.7 crank horsepower and roughly 291.3 wheel horsepower with a 15% drivetrain-loss assumption.

FAQ

Common questions about this calculator.

Short answers to the questions people often ask before or after using the tool.

Question

What is the difference between this and the Horsepower Calculator?

This page estimates engine output from torque and RPM. The separate Horsepower Calculator converts between power units like horsepower, kilowatts, and watts.

Question

Is wheel horsepower exact?

No. Wheel horsepower here is only an estimate based on the drivetrain-loss percentage you choose. Real dyno results vary with the vehicle and testing setup.

Question

Why does the formula use 5252?

5252 is the standard constant used to convert lb-ft of torque and RPM into mechanical horsepower in the common horsepower equation.

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