Power converter
Power Converter – 8 Units, Exact Factors
1 horsepower (mechanical) = 0.7457 kilowatts
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- 1 hp = 0.7457 kW
- 5 hp = 3.7285 kW
- 10 hp = 7.457 kW
- 25 hp = 18.642 kW
- WattsW
- KilowattskW
- MegawattsMW
- Horsepowerhp
- Metric horsepowerPS
- BTU per hourBTU/h
- Tons of refrigeration (US)TR
- Kilocalories per hourkcal/h
- Watts745.7W
- Kilowatts0.7457kW
- Megawatts0.0007457MW
- Horsepower1hp
- Metric horsepower1.0139PS
- BTU per hour2,544.4BTU/h
- Tons of refrigeration (US)0.21204TR
- Kilocalories per hour641.62kcal/h
About power conversions
Mechanical horsepower (hp, 745.7 W) and metric horsepower (PS, 735.5 W) differ by about 1.4%.
Common power conversions
Power units explained
| Unit | System | Definition and notes |
|---|---|---|
| Watt (W) | SI (metric) | Base unit |
| Kilowatt (kW) | SI (metric) | 1 kW = 1,000 W (exact) |
| Megawatt (MW) | SI (metric) | 1 MW = 1,000,000 W (exact) |
| Horsepower (mechanical) (hp) | US & imperial (identical) | 1 hp ≈ 745.69987 WMechanical horsepower: 550 foot-pounds per second, about 745.7 W. |
| Metric horsepower (PS) (PS) | metric (non-SI) | 1 PS = 735.49875 W (exact)Metric horsepower: exactly 735.49875 W. Common in European car specs. |
| BTU per hour (BTU/h) | US & imperial (identical) | 1 BTU/h ≈ 0.29307107 W |
| Ton of refrigeration (TR) | US customary | 1 TR ≈ 3,516.8528 WA ton of refrigeration: 12,000 BTU per hour, about 3,516.85 W. Used for air-conditioner capacity. |
| Kilocalorie per hour (kcal/h) | other | 1 kcal/h ≈ 1.1622222 W |
Horsepower to kilowatts conversion table
| Horsepower (hp) | Kilowatts (kW) |
|---|---|
| 0.1 hp | 0.07457 kW |
| 0.5 hp | 0.37285 kW |
| 1 hp | 0.7457 kW |
| 2 hp | 1.4914 kW |
| 3 hp | 2.2371 kW |
| 4 hp | 2.9828 kW |
| 5 hp | 3.7285 kW |
| 6 hp | 4.4742 kW |
| 7 hp | 5.2199 kW |
| 8 hp | 5.9656 kW |
| 9 hp | 6.7113 kW |
| 10 hp | 7.457 kW |
| 15 hp | 11.185 kW |
| 20 hp | 14.914 kW |
| 25 hp | 18.642 kW |
| 30 hp | 22.371 kW |
| 40 hp | 29.828 kW |
| 50 hp | 37.285 kW |
| 75 hp | 55.927 kW |
| 100 hp | 74.57 kW |
| 250 hp | 186.42 kW |
| 500 hp | 372.85 kW |
| 1,000 hp | 745.7 kW |
Frequently asked questions
Which power units can I convert?
watts (W), kilowatts (kW), megawatts (MW), horsepower (hp), metric horsepower (PS), BTU per hour (BTU/h), tons of refrigeration (TR), kilocalories per hour (kcal/h).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.