| Unit | 1 Watt = | 1 Kilowatt = | 1 HP = |
|---|
SI unit of power. 1 W = 1 joule/sec. Named after James Watt.
1 HP ≈ 745.7 W. Common for engines and motors.
1 BTU/h ≈ 0.293 W. Used for HVAC and heating systems.
Convert between Watts, Kilowatts, Horsepower, BTU/hr, Calories/sec & more — real-time, with formulas.
| Unit | 1 Watt = | 1 Kilowatt = | 1 HP = |
|---|
Power is the rate of energy transfer per unit time. The SI unit is the Watt (W), equal to one joule per second. Power describes how fast work is done or energy is converted.
Metric uses Watts (W, kW, MW, GW). Imperial and US customary systems use horsepower (HP) for engines and BTU/h for heating/cooling. Both systems are widely used worldwide.
Mechanical HP (≈745.7 W) is used for engines. Metric HP (≈735.5 W) is used in some European countries. Electrical HP (746 W exactly) is used for electric motors. This tool uses mechanical HP.
Light bulbs: 5–100 W. Microwave ovens: 600–1200 W. Car engines: 100–400 HP. Power plants: 500–2000 MW. A typical US home uses about 1.2 kW on average.