How to convert horsepower to watts
One horsepower equals 745.7 watts, so multiply the number of horsepower by 745.7:
W = hp × 745.7
hp = W ÷ 745.7 (1 W = 0.001341 hp)
Example: 0.5 hp → 0.5 × 745.7 = 372.85 W.
Going the other way, divide by 745.7, or multiply by 0.001341; the watts to horsepower converter does it for you.
Everyday values
| Horsepower | Watts | For example |
|---|---|---|
| 0.5 hp | 372.85 W | a small pump |
| 1 hp | 745.7 W | one horsepower |
| 2 hp | 1,491.4 W | a garden tool engine |
| 5 hp | 3,728.5 W | a lawn-mower engine, roughly |
When you need this conversion
Multiply horsepower by 745.7 to get watts. Pumps, compressors and small engines in the US are rated in hp; electrical installation work needs watts or kilowatts.
Horsepower to watt conversion table
| hp | W | hp | W |
|---|---|---|---|
| 0.5 hp | 372.85 W | 5.5 hp | 4,101.35 W |
| 1 hp | 745.7 W | 6 hp | 4,474.2 W |
| 1.5 hp | 1,118.55 W | 6.5 hp | 4,847.05 W |
| 2 hp | 1,491.4 W | 7 hp | 5,219.9 W |
| 2.5 hp | 1,864.25 W | 7.5 hp | 5,592.75 W |
| 3 hp | 2,237.1 W | 8 hp | 5,965.6 W |
| 3.5 hp | 2,609.95 W | 8.5 hp | 6,338.45 W |
| 4 hp | 2,982.8 W | 9 hp | 6,711.3 W |
| 4.5 hp | 3,355.65 W | 9.5 hp | 7,084.15 W |
| 5 hp | 3,728.5 W | 10 hp | 7,457 W |
About the units
- Horsepower (hp): mechanical horsepower, 550 foot-pounds per second, about 745.7 W.
- Watt (W): one joule per second, the SI unit of power.
Both are units of power. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many watts are in one horsepower?
One horsepower is 745.7 watts. One watt is 0.001341 horsepower.
How do I convert horsepower to watts?
Multiply the value in horsepower by 745.7. To go back, divide by 745.7.
What is 0.5 hp in watts?
0.5 hp = 372.85 W.
What is 2 hp in watts?
2 hp = 1,491.4 W.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.