The kilowatts to horsepower formula
To convert kilowatts to horsepower, multiply by 1.34102: hp = kW × 1.34102. For example, 10 kW × 1.34102 = 13.41 hp. This is mechanical horsepower; one hp equals about 0.7457 kW. Pair it with the energy converters for related units.
The factor exists because horsepower was defined mechanically, not electrically: one mechanical horsepower is 550 foot-pounds of work per second, which works out to 745.7 watts. Dividing 1,000 W by 745.7 W gives the 1.34102 multiplier. Watts and kilowatts are the SI units, so the kW figure is the physically fundamental one and hp is the historical wrapper around it.
How to convert kW to hp
Enter a power value in kilowatts and the calculator multiplies by 1.34102 to give mechanical horsepower. This is widely used for car, motor, and generator ratings, where Europe quotes kW and the US and UK often quote hp.
Worked examples: a 150 kW electric motor is 150 × 1.34102 = 201.15 hp. A 2.2 kW workshop compressor is 2.95 hp, which is why it is sold as a 3 hp unit. A 5.5 kW standby generator is 7.38 hp on the engine side, although generators are usually rated by electrical output in kVA rather than hp.
Watch which horsepower a spec sheet means. European car brochures often quote PS (Pferdestärke, also written CV or ch), which is 735.5 W rather than 745.7 W, so the same engine reads about 1.4% higher in PS than in hp: 100 kW is 134.10 hp but 135.96 PS. Boiler horsepower, used for steam plant, is different again at roughly 9.81 kW.
If you are checking your work, the joules to calories calculator gives you a second reference point.
Kilowatts to horsepower reference table
| Kilowatts | Horsepower |
|---|---|
| 1 kW | 1.34 hp |
| 10 kW | 13.41 hp |
| 75 kW | 100.58 hp |
| 100 kW | 134.10 hp |
A few anchors for context: a family hatchback sits near 75 kW (100 hp), a hot hatch near 150 kW (200 hp), a 3 kW domestic kettle just 4 hp, and a Formula 1 power unit above 735 kW (about 1,000 hp). Electric cars are almost always specified in kW, so the table above is the quickest way to place them against a petrol equivalent.
The km/h to mph calculator is the natural next step once you have this figure.
Frequently asked questions
- What is 10 kW in horsepower?
- 10 kW equals 13.41 hp (10 × 1.34102).
- What is the kilowatts to horsepower formula?
- hp = kW × 1.34102 (mechanical horsepower).
- How many kilowatts is 1 hp?
- One mechanical horsepower equals about 0.7457 kW.
- Is this metric or mechanical horsepower?
- This uses mechanical (imperial) horsepower. Metric horsepower (PS) is slightly different, at about 1.3596 PS per kW.
- Is a 100 kW electric motor as strong as a 134 hp petrol engine?
- On peak power, yes — the conversion is exact. In practice an electric motor feels stronger because it delivers full torque from zero rpm, while a combustion engine only reaches its rated hp near the top of the rev range.