Power is the rate at which work is done or energy is transferred. All conversions are based on the watt as the base unit.
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What is the Power Converter?
Power is the rate at which energy is transferred or used, typically measured in watts. Different industries and regions use different units: electrical systems use watts (W) and kilowatts (kW), automobiles use horsepower (hp), heating systems use BTU per hour (BTU/h), and mechanical engineering uses kilocalories per hour (kcal/h). A power converter lets you move seamlessly between these units without manual calculation.
How it works
Enter a value and select its unit, then choose the target unit. The converter applies precise conversion factors to give you an exact result. For example, 1 kilowatt equals 1,341 horsepower, or 1 watt equals 3.412 BTU per hour. Results update instantly and can be expressed in scientific notation for very large or very small values.
Forgetting that different regions prefer different units: US often uses BTU/h, Europe uses kW
Mixing up kilowatt (1,000 watts) with megawatt (1,000,000 watts)
Tips
Remember: 1 hp ≈ 746 watts—a quick mental anchor for automotive specifications
Electrical bills are charged in kilowatt-hours (kWh), not kilowatts; check your appliance's wattage rating and hours of use to calculate consumption
Air conditioners and heat pumps are often rated in BTU/h, but their electrical draw is in watts—they are not the same measurement
Use this tool to compare the efficiency of renewable energy sources: a 5 MW wind turbine produces far more power than a typical household solar system (5 kW)
Frequently asked questions
What is the difference between power and energy?
Power is the rate of energy transfer measured in watts; energy is the total amount consumed over time, measured in kilowatt-hours (kWh). A 1,000-watt microwave running for 1 hour uses 1 kWh of energy.
Why do cars list horsepower instead of watts?
Horsepower is the traditional unit from the steam engine era and remains deeply embedded in automotive culture and regulations. It's easier for consumers to understand (larger number = more power), and manufacturers use it for marketing.
How do I calculate my home's electricity usage in kilowatts?
Multiply your appliance's wattage by how many hours it runs per day, divide by 1,000 to get kilowatt-hours. A 1,500W heater running 8 hours daily uses 12 kWh per day.
Is kilowatt the same as kilowatt-hour?
No. A kilowatt (kW) is power (rate); a kilowatt-hour (kWh) is energy (amount used). Think of it like speed (mph) versus distance (miles).
What does BTU/hour measure?
BTU per hour measures heat transfer rate, commonly used for air conditioners and furnaces in the United States. 1 watt = 3.412 BTU/h.
Can I convert power units for solar panels and batteries?
Yes. A 400-watt solar panel produces 400W under peak sunlight. If it runs 5 hours per day, it generates 2 kWh daily. Use the power converter to compare panel ratings or inverter capacities.