Horsepower to kW Calculator
Enter horsepower to convert to kilowatts instantly. Uses the mechanical (imperial) HP standard: 1 HP = 0.7457 kW.
How do you convert horsepower to kilowatts?
Multiply HP by the conversion factor 0.7457: kW = HP × 0.7457. A 10 HP motor has a rated output of 10 × 0.7457 = 7.457 kW. This applies to the mechanical (imperial) horsepower where 1 hp = 745.7 W. Metric horsepower (PS/CV) is slightly smaller at 735.5 W; for metric HP use kW = PS × 0.7355.
HP to kW Conversion Table
| Horsepower (HP) | Kilowatts (kW) | Watts (W) |
|---|---|---|
| 0.5 HP | 0.373 kW | 372.9 W |
| 1 HP | 0.746 kW | 745.7 W |
| 2 HP | 1.491 kW | 1491.4 W |
| 5 HP | 3.729 kW | 3728.5 W |
| 10 HP | 7.457 kW | 7457.0 W |
| 15 HP | 11.186 kW | 11185.5 W |
| 25 HP | 18.643 kW | 18642.5 W |
| 50 HP | 37.285 kW | 37285.0 W |
| 100 HP | 74.570 kW | 74570.0 W |
Formula
Where: kW = kilowatts (mechanical output power), HP = mechanical (imperial) horsepower, 0.7457 = conversion factor (1 hp = 745.7 W = 0.7457 kW).
Note on variants: Metric horsepower (PS, CV, ch) = 735.5 W. Electrical horsepower = 746 W exactly (used in the US for motor nameplate ratings). The difference between metric and electrical HP is less than 0.1 %; for most practical calculations either factor is acceptable.
Frequently Asked Questions
1 horsepower (mechanical) equals 0.7457 kW or 745.7 watts. This is the internationally recognised conversion factor for motor power ratings.
Mechanical (imperial) HP = 745.7 W, used in the US and UK. Metric HP (PS or CV) = 735.5 W, used in Europe for vehicle engines. For electric motors, the mechanical HP standard applies: kW = HP × 0.7457.
1 kW equals 1 ÷ 0.7457 ≈ 1.341 HP. Use the kW to HP calculator for the reverse conversion.
Motor HP ratings represent shaft output power — the mechanical power delivered to the load. Input power from the supply is higher because of motor losses; input kW = output kW ÷ efficiency. A 10 HP (7.457 kW output) motor at 92 % efficiency draws 7.457 ÷ 0.92 ≈ 8.1 kW from the supply.