How many watts is 1 horsepower?

One mechanical horsepower equals 745.69987 watts. This is the standard conversion used for engines, motors, and mechanical equipment in the US.

How do I convert HP to kilowatts?

Multiply HP by 0.74569987. For example, 100 hp = 74.57 kW.

What is mechanical horsepower?

Mechanical horsepower (hp) is the standard used in the US for rating engines, pumps, and motors. It equals 550 foot-pounds per second or 745.69987 watts.

Is this the same as electrical horsepower?

No. Electrical horsepower (used for electric motors in the US) is defined as exactly 746 W — very close but not identical. The difference is about 0.04%. Metric horsepower (PS) equals 735.49875 W.

How accurate is this converter?

The conversion factor 745.69987 W/hp matches the ISO and NIST standard to at least six significant figures, which is precise enough for engineering and equipment selection work.

Horsepower to Watts Converter

Enter horsepower to get watts and kilowatts instantly, plus a quick-reference table for common HP values.

Horsepower to Watts

Horsepower (hp)

Quick presets

Uses mechanical horsepower: 1 hp = 745.69987 W

Result

Enter a horsepower value on the left to see the result.

Common Horsepower Reference

Device / Engine	HP	Watts	kW

Click any row to load that value into the converter.

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Summary

This converter turns any mechanical horsepower value into watts and kilowatts using the standard factor of 1 hp = 745.69987 W. Enter a number, get the result immediately. A reference table lists common power ratings — from small motors to large engines — so you can check real-world context at a glance.

How it works

Type a horsepower value into the input field.
The tool multiplies the HP value by 745.69987 (the mechanical horsepower conversion factor).
The result appears instantly in watts (W) and kilowatts (kW).
Click any row in the reference table to load that HP value into the converter.
Use the Copy button to copy either result to your clipboard.

Use cases

Convert engine output specs from HP to watts for electrical sizing.
Verify generator or motor wattage when only HP ratings are listed.
Compare power ratings between HP-based and watt-based datasheets.
Estimate wattage requirements when selecting motors or drives.
Quick lookup for common appliance and vehicle power levels.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu