Power conversion

Horsepower Calculator

Convert mechanical horsepower, watts and kilowatts using a transparent conversion factor.

Horsepower definitions

Different contexts may use mechanical horsepower, metric horsepower or boiler horsepower. This tool uses mechanical horsepower because it is common in US automotive and equipment specifications.

Example

1,000 watts equals about 1.34 mechanical horsepower because 1 hp is 745.699872 watts. A 100 kW motor is about 134.1 mechanical hp before drivetrain or efficiency losses.

Common mistakes

Check which horsepower definition a source uses. Mechanical horsepower and metric horsepower are close, but not identical, and engine output may be measured differently from wheel output.

Limitations

This is a power unit converter. It does not estimate vehicle acceleration, torque, drivetrain loss, battery limits or real engine performance.

Last reviewed: 2026-05-17

Before relying on this result

Use this calculator together with the formula, assumptions, limitations and examples on the page. If the topic involves health, tax, lending, investment, legal, safety or current-rate decisions, treat the number as an estimate and check the relevant primary source or professional guidance.

Calculator metadata last reviewed: 2026-05-14.