How many watts is 1 horsepower?

It depends on the HP standard. One mechanical horsepower equals 745.69987 watts. One electrical horsepower equals exactly 746 watts. One metric horsepower (PS or CV) equals 735.49875 watts.

What is the difference between mechanical, electrical, and metric horsepower?

Mechanical (imperial) horsepower (745.69987 W) is the common US standard for engines and motors. Electrical horsepower (746 W) is used for electric motor ratings in the US and is defined as exactly 746 W. Metric horsepower (PS or CV, 735.49875 W) is used in Europe and Asia for vehicle power ratings and is slightly lower than mechanical hp.

Why do car manufacturers list different HP figures for the same model in different countries?

European manufacturers historically use metric horsepower (PS), while American manufacturers use mechanical horsepower. The difference is about 1.4%, so a 200 PS European car is roughly 197 mechanical hp in US figures.

How do I convert horsepower to kilowatts?

Multiply the HP value by the watt conversion factor, then divide by 1000. For mechanical hp: kW = hp x 0.74569987. For metric PS: kW = PS x 0.73549875. For electrical hp: kW = hp x 0.746.

Can I convert watts back to horsepower with this tool?

Yes. Switch to the Watts to HP tab, enter the watt value, and the tool divides by each HP standard factor to show mechanical, electrical, and metric horsepower simultaneously.

Is this tool accurate enough for engineering use?

The conversion factors match ISO and IEEE standards to six or more significant figures, which is sufficient for most engineering, specification, and equipment selection work.

Horsepower to Watts Converter

Enter horsepower (mechanical, electrical, or metric PS) to instantly get watts and kilowatts. Two-way conversion included.

Power Converter

Horsepower value

HP type

Quick presets

Result in Watts & Kilowatts

Enter a horsepower value on the left to see results.

Common Power Reference

Device / Motor	hp (mech)	Watts	kW

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Summary

This tool converts any horsepower value to watts and kilowatts using the three internationally recognized HP standards: mechanical (imperial) horsepower, electrical horsepower, and metric horsepower (PS/CV). Enter an HP value, choose the HP type, and the watt and kilowatt equivalents appear immediately. A reverse mode lets you enter watts to get back horsepower. A reference table of common motors and machines is included for quick lookup.

How it works

Enter a horsepower value in the HP input field.
Select the horsepower type: Mechanical, Electrical, or Metric (PS).
The tool multiplies the HP value by the appropriate conversion factor to get watts.
Mechanical hp uses 1 hp = 745.69987 W; electrical hp uses 1 hp = 746 W; metric PS uses 1 PS = 735.49875 W.
The kilowatt result is the watt value divided by 1000.
Switch to Watts to HP mode to run the conversion in reverse.
Click any row in the reference table to load that value into the converter.

Use cases

Convert engine specs from horsepower to watts for electrical system sizing.
Compare vehicle power ratings between American and European HP standards.
Verify electric motor output when datasheets list power in different units.
Convert pump or HVAC motor ratings for equipment selection.
Cross-check generator output specs listed in HP against watt-based requirements.
Quickly look up where a specific machine falls in the reference power table.

Frequently Asked Questions

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