Why does the formula use 5252?

It comes from the definition of one horsepower (33,000 lb-ft per minute) divided by 2π.

Is wheel horsepower the same?

No. Wheel figures are lower because of drivetrain losses.

Horsepower ↔ Torque Calculator

Power and torque are linked by engine speed. Enter torque and RPM to get power, or power and RPM to get torque.

Results

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Formula

Horsepower = torque (lb-ft) × RPM ÷ 5252. In metric: kW = torque (Nm) × RPM ÷ 9549. That is why hp and lb-ft curves always cross at 5252 RPM on a dyno chart.

1 lb-ft = 1.3558 Nm, 1 hp = 0.7457 kW, 1 PS = 0.7355 kW.

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FAQ

Why does the formula use 5252?: It comes from the definition of one horsepower (33,000 lb-ft per minute) divided by 2π.
Is wheel horsepower the same?: No. Wheel figures are lower because of drivetrain losses.

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