Power Converter
Convert power between horsepower, kilowatts, watts, BTU per hour and tons of refrigeration.
Horsepower and kilowatts
Power is energy per unit of time. Car engines are rated in horsepower in the US and in kilowatts (or metric horsepower, PS) in Europe.
- Mechanical horsepower (hp): 745.7 watts, the US and UK standard.
- Metric horsepower (PS, CV): 735.5 watts, about 1.4% less.
- Kilowatt: 1,000 watts; 1 kW is 1.341 hp.
A 300 hp engine produces 300 × 0.7457 = 223.7 kW. An electric car rated at 150 kW is about 201 hp.
Heating and cooling
Air conditioners in the US are sized in BTU per hour or "tons". One ton of refrigeration is 12,000 BTU/h, about 3.52 kW of cooling. A 9,000 BTU/h window unit delivers roughly 2.6 kW.
Frequently asked questions
How do I convert hp to kW?
Multiply horsepower by 0.7457. For example, 200 hp is 149.1 kW.
What is the difference between hp and PS?
PS (metric horsepower) is 735.5 watts; mechanical hp is 745.7 watts, so 100 hp is about 101.4 PS.
How many BTU is 1 ton of AC?
One ton of cooling is 12,000 BTU per hour.
Last reviewed October 2026. Results are estimates; check important decisions with a qualified professional.