Kw to Hp Converter

Quick Answer

Last updated: 11 November 2026 ·How we calculate this: NIST horsepower definitions

How This Kw to Hp Converter Works

Electric cars, motors, generators and European car brochures list power in kilowatts, while US car ads and small engines use horsepower. Choose the direction and the kind of horsepower, enter the power and press Calculate. The converter shows the answer in all three horsepower types and in watts, with the formula.

How to Use the Kw to Hp Converter

1. Choose kilowatts to horsepower or horsepower to kilowatts.
2. Choose the horsepower type.
3. Enter the power.
4. Press Calculate.
5. Read the power in all three horsepower types and in watts.

Kw to Hp Formulas

• Mechanical hp: 1 hp = 550 ft·lbf/s = 745.6999 W
• Metric hp (PS): 1 PS = 75 kgf·m/s = 735.49875 W
• Electric hp: 1 hp = 746 W exactly
• hp from kW: hp = kW × 1,000 ÷ 745.700
• kW from hp: kW = hp × 745.700 ÷ 1,000

Key Terms

• Kilowatt (kW): 1,000 watts, the SI unit of power.
• Horsepower (hp): 550 ft·lbf per second, 745.7 W.
• PS: metric horsepower, 735.5 W.
• bhp: brake horsepower, measured at the engine.
• Watt (W): one joule per second.

Worked Example

An electric car has a 250 kW motor. What is that in horsepower?

• Mechanical: 250 × 1,000 ÷ 745.700 = 335.3 hp
• Metric: 250 × 1,000 ÷ 735.499 = 339.9 PS
• So a US brochure would say about 335 hp and a German one about 340 PS.

Going the other way, a 5 hp lawn mower engine is 5 × 0.7457 = 3.73 kW.

Real-Life Examples

• Electric cars: a 150 kW motor is 201 hp.
• European cars: 110 kW is 150 PS or 148 hp.
• Generators: a 7.5 kW unit is about 10.1 hp.
• Pumps and motors: a 2 hp motor is 1.492 kW (electric hp).

Horsepower vs PS

• hp (mechanical): 745.70 W, used in the US and UK.
• PS (metric hp): 735.50 W, used in Europe.
• Difference: 1 hp = 1.0139 PS.

Kw to Hp Chart

1 hp = 745.70 W; 1 PS = 735.50 W.

Three Kinds of Horsepower

James Watt defined horsepower in the 1780s to compare steam engines with draft horses: 550 foot-pounds of work per second. That mechanical horsepower is used in the US and UK. Continental Europe adopted a metric version based on lifting 75 kilograms one meter per second, the Pferdestärke (PS), cheval-vapeur (CV, ch) or paardenkracht (pk), which is about 1.4% smaller. Electric motors in the US are rated in electric horsepower of exactly 746 watts.

Car makers now quote kilowatts by law in the EU, often with PS in brackets, so the same engine can be described as 110 kW, 150 PS and 148 hp. Brake horsepower (bhp) is mechanical horsepower measured at the engine’s crankshaft; wheel horsepower measured on a dynamometer is lower because of losses in the transmission. This converter changes units only; it does not estimate those losses.

Power also is not the same as torque. Two engines with the same horsepower can feel very different if one makes its power at high revs and the other produces strong torque low down. Electric motors deliver full torque from a standstill, which is why an electric car with modest kilowatts can feel quick. When comparing vehicles or motors, check the power figure in the same unit, at the same measuring point, and look at torque as well.

Common Mistakes to Avoid

• Mixing hp and PS. 150 PS is 148 hp.
• Confusing kW and kWh. kW is power; kWh is energy.
• Expecting wheel power. Engine ratings are higher than wheel power.
• Using 0.75 for big numbers. 400 hp is 298.3 kW, not 300 kW.
• Dividing when you should multiply. kW is the smaller number.

Frequently Asked Questions

References & Sources