Power Converter
Convert power between watts, kilowatts, metric horsepower (PS) and mechanical horsepower (hp). Great for cars, motors and appliances.
All units at once
Car power reference (hp (mechanical) / kW / PS (metric hp))
Conversion rules and sources
| Unit | Rule | Reference |
|---|---|---|
| hp (mechanical) | 1 hp = 745.69987158 W | NIST SP 811 |
| PS (metric hp) | 1 PS = 735.49875 W | NIST SP 811 |
| BTU/h (IT) | 1 BTU/h = 0.293071070 W | NIST SP 811 |
| Refrigeration ton (RT) | 1 RT = 3.516853 kW | NIST SP 811 |
Conversion factors: NIST SP 811. Electrical power terminology: IEEE. Checked 2026-07-21.
Energy over time: energy converter · fuel economy: MPG / L/100km.
Electrical power from V × A × PF
For DC or a simple single-phase estimate. This is separate from the unit converter because VA is not a watt unit.
Convert power units
Convert named power units with sourced factors, or calculate real electrical power separately from voltage, current, and power factor.
FAQ
Which units are supported?
mW, W, kW, MW, BTU/h (IT), refrigeration ton (RT), hp (mechanical), and PS (metric hp).
How many watts are in 1 horsepower?
1 hp (mechanical) = 745.69987158 W, while 1 PS (metric hp) = 735.49875 W. They are different units and are labeled separately.
Is volt-ampere the same as watt?
Not generally. V × A gives apparent power in VA. Real power is V × A × power factor in W, so PF below 1 makes real power lower than apparent power.
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