What this tool does
Converts between watts, kilowatts, megawatts, horsepower (mechanical and metric), BTU/hour, and calories/second.
Converter and calculator
Power Converter
Convert between watts, kilowatts, horsepower (mechanical and metric), BTU/hour, and more. Covers electrical, mechanical, and thermal power.
Complete guide
How to use Power Converter
Unit converters guide for power converter users.
Power is the rate of energy transfer. Watts are the SI unit; horsepower is used for engines (1 mechanical hp = 745.7 W); BTU/hour is used in HVAC. This converter handles all common power units across electrical, mechanical, and thermal engineering.
Key conversions
1 mechanical hp = 745.7 W. 1 metric hp = 735.5 W. 1 kW = 1,000 W. 1 BTU/h = 0.293 W.
How to use it
Enter a value and select the source unit. All other units update instantly.
Quick checklist
- Mechanical hp (used in the US) ≠metric hp (used in Europe).
- 1 horsepower ≈ 746 watts (mechanical).
- Your electricity bill is in kWh (kilowatt-hours), not kilowatts.
- Home appliances: kettle ~2 kW, microwave ~1 kW, light bulb ~10 W (LED).
Answers
Power Converter FAQs
How many watts in a horsepower?
1 mechanical horsepower = 745.7 watts. 1 metric horsepower = 735.5 watts.
What is the difference between mechanical and metric horsepower?
Mechanical hp (US) = 745.7 W. Metric hp (Europe) = 735.5 W. Car specs use metric hp in Europe and mechanical hp in the US.
How many watts is 1 BTU per hour?
1 BTU/h = 0.29307 W.
How is power different from energy?
Power is the rate of energy use (watts). Energy is the total amount used over time (watt-hours). 1 kW running for 1 hour = 1 kWh of energy.