Power Converter
Convert between watts, kilowatts, horsepower, BTU per hour, and other power units instantly.
How to Use the Power Converter
- Enter Power Value: Type the number you want to convert
- Select Source Unit: Choose the unit you're converting from (watts, horsepower, etc.)
- Choose Target Unit: Pick the unit you need for your calculation
- View Conversion: The result appears instantly with full precision
- Swap Units: Click the exchange button to reverse the conversion direction
Power Units Explained
Watts (W) and Kilowatts (kW)
Watts measure the rate of energy transfer. One watt equals one joule per second. Household appliances show power ratings in watts. A typical microwave uses 1,000 watts (1 kW), while a laptop might draw 45-65 watts. Electric companies bill based on kilowatt-hours, which combines power (kW) with time.
Horsepower (hp)
Horsepower originated from comparing engine power to horse-drawn equipment. One mechanical horsepower equals 746 watts. Car engines, electric motors, and pumps often use horsepower ratings. A 200 hp engine produces about 149 kilowatts of power.
BTU per Hour (BTU/h)
This unit measures thermal power output, commonly used for heating and cooling equipment. Air conditioners, furnaces, and boilers show capacity in BTU/h. One BTU/h equals about 0.293 watts. A 12,000 BTU/h air conditioner equals roughly 3.5 kW.
Metric vs Imperial Horsepower
Two horsepower standards exist. Mechanical horsepower (hp or bhp) equals 746 watts and is used in the US. Metric horsepower (PS or CV) equals 735 watts and appears in European specifications. Always check which standard applies when comparing equipment.
Common Power Conversions
Quick Reference
Real-World Examples
Practical Applications
Automotive and Engines
- Comparing vehicle engine performance across different markets
- Selecting electric motor size for machinery and equipment
- Converting generator output ratings for power backup systems
- Evaluating pump capacity for water and fluid systems
Home and Appliances
- Calculating electrical circuit requirements for appliances
- Sizing HVAC systems for heating and cooling needs
- Comparing energy efficiency across different power ratings
- Understanding solar panel output and inverter capacity
Quick Tip: When shopping for appliances or equipment, higher wattage usually means more power but also higher energy costs. Balance power needs with efficiency ratings to find the best option for your situation.
Frequently Asked Questions
Why do European cars show different horsepower numbers?
Europe uses metric horsepower (PS), while the US uses mechanical horsepower (hp). A car with 200 PS equals about 197 hp. The difference is small but can cause confusion when comparing specifications. Always check which standard is being used.
How do I convert between power and energy?
Power measures the rate of energy use, while energy is the total amount consumed. Multiply power by time to get energy. For example, a 1,000-watt appliance running for 2 hours uses 2,000 watt-hours (2 kWh) of energy.
What size generator do I need for my home?
Add up the wattage of all appliances you want to run simultaneously. Include startup surge for motors (typically 2-3x running wattage). A typical home needs 5,000-7,000 watts for essentials. Whole-house systems range from 15,000-20,000 watts.
Why is my AC unit rated in BTU/h instead of watts?
HVAC industry tradition uses BTU/h for cooling and heating capacity. This measures thermal power output, not electrical power input. A 12,000 BTU/h unit might draw 3,500 watts of electricity while producing 12,000 BTU/h of cooling.
Do electric motors have the same power rating everywhere?
Motor nameplates show output power, but the unit varies. US motors use hp, European motors use kW or PS. A 1 hp motor outputs 746 watts regardless of where it's made. Always convert to the same unit when comparing motors.