Watt to Kilowatt Converter
Quickly convert from Watt to Kilowatt.
How to convert
Formula:
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Power is the rate at which energy is produced or consumed. It is essentially energy over time.
Where is it used?
In car engines (horsepower), in bulbs and appliances (Watts), and in power plants.
Examples:
• A typical kettle consumes 2,000-2,400 Watts.
• A small city car has about 75-100 horsepower.
• 1 Horsepower is about 746 Watts.
Power conversion matters every time you compare engine specs, calculate electricity bills, or understand heating systems. Watts, horsepower, kilowatts, and BTU/hour are all measuring the same thing — the rate of energy transfer — but in very different scales.
Power is the rate at which energy is transferred or work is done. The SI unit is the watt (W), defined as one joule per second. One kilowatt (kW) = 1,000 W. Horsepower (hp) was defined by James Watt to compare steam engines to horses — 1 mechanical hp ≈ 745.7 W.
Where is it used?
- Electricity — Appliances rated in watts or kilowatts; electricity bills calculated in kilowatt-hours (kWh = kW × hours).
- Automotive — Engine output in horsepower (US/UK) or kilowatts (Europe). 100 hp ≈ 74.6 kW.
- HVAC & Cooling — Air conditioners rated in BTU/hour or tons of refrigeration (1 ton = 12,000 BTU/h ≈ 3.517 kW).
- Industrial — Motors and generators rated in kW or MW; power plants in megawatts (MW) or gigawatts (GW).
- Sports & Fitness — Cycling power in watts; metabolic rate in watts per kilogram body weight.
Common Conversion Mistakes
Confusing power (W) with energy (Wh)
A 100 W bulb running for 10 hours uses 1,000 Wh = 1 kWh of energy. Power is the rate; energy is the total consumption. Your electricity bill charges per kWh, not per kW.
Using wrong horsepower type
Mechanical (imperial) hp = 745.7 W. Metric hp (PS, CV) = 735.5 W. Electric hp = 746 W exactly. A European car with 100 PS has 98.6 mechanical hp — close but not equal.
Misunderstanding ton of refrigeration
A 1-ton AC unit doesn't weigh a ton — it can remove heat at the rate needed to melt 1 short ton of ice per day: 12,000 BTU/h ≈ 3.517 kW.
Confusing kVA with kW
kVA (kilovolt-amperes) is apparent power; kW is real power. kW = kVA × power factor. For resistive loads (heaters), power factor = 1 so kW = kVA. For motors and electronics, power factor < 1.
Quick Reference Table
| From | To |
|---|---|
| 1 horsepower (mechanical) | 745.7 W |
| 1 horsepower (metric, PS) | 735.5 W |
| 1 kilowatt | 1.341 hp (mechanical) |
| 1 ton of refrigeration | 3,517 W (3.517 kW) |
| 1 BTU/hour | 0.2931 W |
| 1 megawatt | 1,000 kW |
| 1 watt | 1 joule/second |
| 100 kW | 134.1 hp |
Frequently Asked Questions
How do I convert horsepower to kilowatts?
Multiply mechanical hp by 0.7457 to get kW. Or divide kW by 0.7457 to get hp. Example: 200 hp × 0.7457 = 149.1 kW. A quick estimate: kW ≈ hp × 0.75.
What is the difference between kW and kWh?
kW (kilowatt) is power — the rate of energy use right now. kWh (kilowatt-hour) is energy — the total amount consumed over time. A 2 kW heater running for 3 hours uses 6 kWh. Your utility bills you for kWh.
How powerful is the human body?
A fit human can sustain about 200-300 W of mechanical power during vigorous exercise. Peak sprint power can reach 1,000-2,000 W for a few seconds. Tour de France cyclists average ~400 W for hours.
What is a gigawatt?
1 GW = 1,000,000,000 W = 1 million kW. A large nuclear power plant generates about 1 GW. The famous Back to the Future '1.21 gigawatts' would power about 1 million homes.
Sources & Standards
- International Bureau of Weights and Measures (BIPM)
- National Institute of Standards and Technology (NIST)
- International Electrotechnical Commission (IEC)
Reviewed by The Unit Hub Editorial Team · March 2026