Convert Watts to Horsepower
1 watt (W) equals 0.00134102209 horsepower (hp).
1 W = 0.00134102209 hp
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt to horsepower converter to paste a column from Excel.
How to Convert Watt to Horsepower
- 1 W = 0.00134102209 hp
- 1 hp = 745.6998716 W
- Example: convert 15 W to hp: 15 W = 15 × 0.00134102209 hp = 0.02011533134 hp
Reference conditions. hp: Mechanical (imperial) horsepower, 550 ft·lbf/s. Metric horsepower (PS) is about 1.4 % smaller.
Formula
hp = W × 0.001341022089595
or hp = W ÷ 745.6998715823
Derivation from SI units:
- 1 W = 1 J/s = 1 kg·m²·s⁻³
- 1 hp = 550 ft·lbf/s = 745.69987158227 W
Both units are defined exactly, so the factor is exact. Watt definition: watt; Horsepower definition: horsepower.
Worked examples
- An electric motor drawing 746 W of output is about 1.000402479 hp.
746 W × 0.00134102209 = 1.000402479 hp - A 250 W e-bike motor is 0.3352555224 hp.
250 W × 0.00134102209 = 0.3352555224 hp
Watt to Horsepower conversion table
| Watts (W) | Horsepower (hp) |
|---|---|
| 1 W | 0.00134102209 hp |
| 5 W | 0.006705110448 hp |
| 10 W | 0.0134102209 hp |
| 40 W | 0.05364088358 hp |
| 60 W | 0.08046132538 hp |
| 100 W | 0.134102209 hp |
| 250 W | 0.3352555224 hp |
| 500 W | 0.6705110448 hp |
| 746 W | 1.000402479 hp |
| 1000 W | 1.34102209 hp |
| 1500 W | 2.011533134 hp |
| 2000 W | 2.682044179 hp |
| 3500 W | 4.693577314 hp |
| 5000 W | 6.705110448 hp |
| 10000 W | 13.4102209 hp |
Where it's used
Small motor and appliance outputs in watts are converted to horsepower for US equipment and comparisons.
Watt to other power units
| Conversion | 1 W equals |
|---|---|
| watt to milliwatt | 1000 mW |
| watt to kilowatt | 0.001 kW |
| watt to megawatt | 0.000001 MW |
| watt to horsepower | 0.00134102209 hp |
| watt to metric horsepower | 0.001359621617 PS |
| watt to BTU per hour | 3.412141633 BTU/h |
| watt to refrigeration ton | 0.0002843451361 TR |
| watt to kilocalorie per hour | 0.8598452279 kcal/h |
| watt to foot-pound per second | 0.7375621493 ft·lbf/s |
Frequently asked questions
How many watts is 1 horsepower?
1 hp = 745.6998716 W.
How many horsepower are in 1 watt?
1 W = 0.00134102209 hp.
How do I convert watts to horsepower?
Multiply the value in W by 0.00134102209, or divide it by 745.6998716. For example, 15 W × 0.00134102209 = 0.02011533134 hp.
Is the W to hp conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "horsepower (550 ft·lbf/s)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Watts to Horsepower. Retrieved October 17, 2026, from https://scientificconverters.com/power/watts-to-horsepower/
IEEE
Scientific Converters, "Convert Watts to Horsepower," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/power/watts-to-horsepower/