Power Converter
Convert watts, kilowatts, horsepower (mechanical and metric), BTU per hour and tons of refrigeration.
About the Power Converter
Power is energy per second; one watt is one joule per second. Car engines are rated in horsepower: mechanical (imperial) horsepower is 745.7 W, while metric horsepower (PS, CV) is 735.5 W.
Air conditioners are sized in BTU per hour or tons of refrigeration: one ton is 12,000 BTU/h, about 3.517 kW of cooling.
The formula
Result = Value × (size of the “from” unit ÷ size of the “to” unit)
- 1 W
- 1 W
- 1 kW
- 1,000 W
- 1 MW
- 1,000,000 W
- 1 hp
- 745.6998716 W
- 1 PS
- 735.49875 W
- 1 BTU/h
- 0.2930710702 W
Every power unit is converted through watt using its exact definition.
Common conversions
| From | To |
|---|---|
| 1 hp | 0.7456998716 kW |
| 1 kW | 1.34102209 hp |
| 1 PS | 0.73549875 kW |
| 1 kW | 3,412.141633 BTU/h |
| 1 TR | 3.516852842 kW |
| 12,000 BTU/h | 3,516.852842 W |
How to read your result
- Check which horsepower your source uses; European car specs often use PS.
Worked example
Example: 110 horsepower (mechanical) = 82.02698587 kW
- Inputs: Value: 110; From: Horsepower (mechanical) (hp); To: Kilowatt (kW).
- Formula: Result = Value × (size of the “from” unit ÷ size of the “to” unit)
- Multiply by the number of kW in one hp 110 × 0.7456998716 = 82.02698587 kW
- Result: 110 horsepower (mechanical) = 82.02698587 kW
- 1 hp = 0.7456998716 kW
- 1 kW = 1.34102209 hp
Questions people ask
How many kW is 1 hp?
0.7457 kW for mechanical horsepower, 0.7355 kW for metric horsepower (PS).
What size is a 1.5 ton AC?
18,000 BTU/h, about 5.28 kW of cooling.