How to Convert Power Units
Convert between different power units instantly. Our converter handles watts, kilowatts, horsepower, BTU/hour, and more-essential for understanding electrical appliances, vehicles, and HVAC systems.
Understanding Power Units
Power measures the rate of energy transfer or work done per unit time. Watts (W) and kilowatts (kW) are standard SI units. Horsepower (hp) is used for engines and motors. BTU/hour is common for heating and cooling systems.
Common Power Conversions
Key relationships: 1 kilowatt = 1,000 watts, 1 horsepower = 745.7 watts ≈ 0.746 kW, 1 BTU/hour = 0.293 watts.
Example:
A 150 hp engine = 150 × 745.7 = 111,855 watts ≈ 112 kW. A 1,500W space heater = 1,500 × 3.41 = 5,118 BTU/hour.
Common Use Cases
Real-world applications for this calculator
Vehicles
Compare engine power ratings in horsepower (US) vs kilowatts (Europe/Australia).
Electrical Appliances
Understand appliance wattage for energy consumption and electrical capacity planning.
HVAC Systems
Convert between BTU/hour and watts when sizing heating and cooling equipment.
Tips
- Quick estimate: hp × 0.75 ≈ kW, kW × 1.34 ≈ hp.
- Appliance running cost: (watts × hours × rate) ÷ 1000 = cost.
- Electric car motors are rated in kW; 100 kW ≈ 134 hp.
Frequently Asked Questions
How do I convert horsepower to kilowatts?
Multiply horsepower by 0.746 to get kilowatts. For example, 200 hp = 200 × 0.746 = 149.2 kW.
How do I convert kilowatts to horsepower?
Multiply kilowatts by 1.341 to get horsepower. For example, 100 kW = 100 × 1.341 = 134.1 hp.
What is a watt?
A watt is the SI unit of power equal to one joule per second. A 100-watt light bulb uses 100 joules of energy every second.
How much power does a typical home use?
Average US home power consumption is about 1.2 kW (average over 24 hours), or about 30 kWh per day. Peak usage during high-demand times can be 5-10 kW or more.