How to use this calculator
- Enter a power value.
- Choose the from and to units. Mechanical (hp) and metric (PS) horsepower differ slightly.
Formula
Power is energy per unit time; the watt is one joule per second.
1 hp (mechanical) = 745.6999 W
1 PS (metric hp) = 735.49875 W
1 BTU/h = 0.29307 W
1 ton of refrigeration = 12,000 BTU/h ≈ 3.517 kW
Examples
- 100 hp × 0.7457 = 74.57 kW.
- A 12,000 BTU/h air conditioner ≈ 3.52 kW of cooling.
Frequently asked questions
What's the difference between hp and PS?
Mechanical horsepower (US/UK) is about 745.7 W; metric horsepower (PS, CV, ch) used in Europe is about 735.5 W.
Power vs. energy?
Power is the rate of energy use. A 2 kW heater running for 3 hours uses 6 kWh of energy.
How do I size an air conditioner?
Use the BTU calculator to estimate the cooling capacity for a room.