Power Converter
Convert between Watts, Kilowatts, Megawatts, Horsepower, BTU/hour, and more instantly.
Quick Reference
How to Convert Power Units
Power is the rate at which energy is transferred or converted. This converter works by converting every input to the base unit (Watts), then to the target unit. Power measurement matters for engines, electrical appliances, and industrial equipment.
Common Conversion Factors
| From | To | Multiply by |
|---|---|---|
| Horsepower (mech) | Watts | 745.7 |
| Horsepower (metric) | Watts | 735.499 |
| Kilowatt | Watts | 1,000 |
| Megawatt | Watts | 1,000,000 |
| BTU/hour | Watts | 0.29307 |
| Horsepower | Kilowatts | 0.7457 |
| Kilowatt | Horsepower | 1.341 |
Power in Everyday Life
Home appliances: A microwave oven uses about 1,000 W (1 kW), an LED bulb uses 10 W, and a hair dryer uses 1,500—2,000 W. Vehicles: A typical sedan has 150×200 hp, a sports car 300—500 hp, and a Formula 1 engine about 1,000 hp (746 kW). Electric vehicles rate motor power in kW — a Tesla Model 3 has about 211 kW (283 hp).
Power Quick Reference
| HP (mech) | kW | Watts | BTU/h |
|---|---|---|---|
| 1 | 0.746 | 745.7 | 2,544 |
| 5 | 3.729 | 3,728.5 | 12,722 |
| 10 | 7.457 | 7,457 | 25,444 |
| 100 | 74.57 | 74,570 | 254,443 |
| 500 | 372.85 | 372,850 | 1,272,214 |
Power is the rate at which energy moves
Energy is a quantity; power is the rate at which that quantity is produced, consumed, or transferred. The SI unit is the watt — one joule per second. A 100 W lightbulb consumes 100 joules every second; a 5 kW heat pump moves 5,000 joules of heat per second. Multiply power by time and you get energy: 100 W × 10 hours = 1,000 Wh = 1 kWh.
Conversion factors
| From | To | Factor |
|---|---|---|
| 1 watt | horsepower (mechanical) | 0.001341 |
| 1 horsepower (mechanical/SAE) | watts | 745.7 |
| 1 metric horsepower (PS, ch) | watts | 735.5 |
| 1 kilowatt | horsepower | 1.341 |
| 1 BTU/hour | watts | 0.293 |
| 1 ton of refrigeration | watts | 3,517 (12,000 BTU/h) |
| 1 foot-pound/second | watts | 1.356 |
Where each unit appears
- Watts and kilowatts — almost everything electrical: appliances, motors, EVs, solar inverters, server racks.
- Horsepower (HP) — internal-combustion engines in North America. SAE HP (mechanical, 745.7 W) for cars, electrical HP (746 W) for motors.
- Metric horsepower (PS, CV, ch) — European and Japanese car spec sheets. Slightly smaller than SAE HP, which is why a "200 PS" car is roughly a "197 HP" car.
- BTU/hour — heating and cooling capacity in the US. A "10,000 BTU" window AC produces 10,000 BTU of cooling per hour ≈ 2,930 W ≈ 0.83 tons.
- Tons of refrigeration — commercial HVAC. One ton historically meant the cooling rate of one ton of ice melting per day.
Worked example: matching a generator to a load
A homeowner wants to back up a 3-ton central AC during outages. 3 tons × 3,517 W = 10,551 W of cooling power, but compressors draw 2–5× that during start-up surge. A 14 kW continuous generator with 25 kW surge handles it; a 7 kW unit will trip on the first compressor start. Reading nameplate data in mixed units (BTU/h for the AC, kW for the generator, HP for the well pump) is exactly the daily situation a converter solves.