How many kilowatts is 1 horsepower?

1 mechanical horsepower equals 0.7457 kW (745.7 W). 1 electric horsepower equals exactly 0.746 kW. 1 metric horsepower (PS) equals approximately 0.7355 kW (735.499 W).

Which horsepower type should I use for car engines?

North American manufacturers use SAE mechanical horsepower. European manufacturers often list metric horsepower (PS or CV). Check the specification sheet footnotes to confirm which standard applies before converting.

What is the difference between mechanical and electric horsepower?

Mechanical (imperial) horsepower is defined as 550 foot-pounds per second, equal to 745.69987 W. Electric horsepower is defined as exactly 746 W. The difference is less than 0.04%, but matters in precise engineering calculations.

What is metric horsepower (PS or CV)?

Metric horsepower (Pferdestärke in German, cheval-vapeur in French) is defined as the power needed to lift 75 kg by 1 meter in 1 second, equal to 735.499 W. It is slightly less than mechanical horsepower and is common in European automotive ratings.

Can I convert fractional horsepower values?

Yes. The input accepts any positive number including decimals. For example, 0.5 hp equals approximately 0.3729 kW (mechanical).

Horsepower to Kilowatts Calculator

Enter horsepower and instantly get the equivalent in kilowatts using mechanical, electric, or metric (PS) conversion factors.

Power Input

Horsepower Type

Horsepower (hp)

Conversion Formulas

1 hp (mechanical) = 0.745700 kW
1 hp (electric) = 0.746000 kW
1 hp (metric, PS) = 0.735499 kW

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Summary

This calculator converts horsepower (hp) to kilowatts (kW) using the selected horsepower definition: mechanical (imperial) horsepower at 745.7 W, electric horsepower at exactly 746 W, or metric horsepower (PS/CV) at 735.499 W. It also displays the selected conversion in watts, milliwatts, and BTU per hour.

How it works

Enter a power value in horsepower in the input field.
Select the horsepower type: mechanical (default), electric, or metric (PS/CV).
The tool multiplies by the matching constant: 1 mech hp = 0.745700 kW, 1 elec hp = 0.746000 kW, 1 metric hp = 0.735499 kW.
The selected conversion updates instantly in kW, W, mW, and BTU per hour as you type.
Click any result row to copy the value to your clipboard.

Use cases

Convert car engine ratings from hp to kW for European spec sheets.
Size electric motors and inverters based on hp-rated loads.
Compare generator output listed in hp against kW power requirements.
Convert electric vehicle power figures between US and EU markets.
Academic coursework and engineering problems involving power units.
Verify pump or compressor nameplate ratings in mixed-unit environments.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu