Power Converter: Watts, Kilowatts, Horsepower & BTU/h
Convert watts, kilowatts, megawatts, horsepower, BTU per hour and foot-pounds per second — with a full conversion table for every value.
Formulas verified against standard references. Calculator logic tested with verified worked examples. Last reviewed: October 2026. Our methodology
How Power Conversion Works
Power is the rate at which energy is used or produced. Every power unit can be expressed in watts: multiply the value by the unit's watt factor to get watts, then divide by the target unit's factor to get the converted value.
Power is one of several everyday physical quantities you may need to convert. For a related quantity, try the pressure converter.
Temperature is measured differently, with an offset as well as a scale, so use the temperature converter for degrees Celsius and Fahrenheit.
Power Units and Watt Factors
Use watts as the common middle step. The table below gives the exact watt factor for each unit this converter supports. Horsepower here is mechanical horsepower.
| Unit | Symbol | Watts in one unit |
|---|---|---|
| Watt | W | 1 |
| Kilowatt | kW | 1,000 |
| Megawatt | MW | 1,000,000 |
| Horsepower (mechanical) | hp | 745.699872 |
| BTU per hour | BTU/h | 0.29307107 |
| Foot-pound per second | ft-lb/s | 1.35581795 |
Worked Example: 1 Kilowatt
Convert 1 kilowatt to watts, horsepower and BTU per hour. First, 1 kilowatt is 1000 watts. Then divide 1000 watts by each target factor.
1000 ÷ 745.699872 = 1.34102 horsepower. 1000 ÷ 0.29307107 = 3412.14 BTU per hour. So 1 kilowatt = 1000 watts = 1.34102 horsepower = 3412.14 BTU per hour.
| Unit | Value for 1 kilowatt |
|---|---|
| Watt (W) | 1,000 |
| Kilowatt (kW) | 1 |
| Megawatt (MW) | 0.001 |
| Horsepower (hp) | 1.34102 |
| BTU per hour (BTU/h) | 3,412.14 |
| Foot-pound per second (ft-lb/s) | 737.56 |
Choosing the Right Unit
Use watts for small devices, kilowatts for home appliances and solar panels, and megawatts for power stations. Engine power is usually quoted in horsepower, while heating and cooling equipment is often rated in BTU per hour.
When comparing two ratings, convert both to watts first. That avoids mistakes from mixing units, such as comparing a 1500-watt heater directly with a 2-horsepower motor.
Frequently asked questions
How many watts are in 1 kilowatt?
1,000 watts.
How many horsepower is 1 kilowatt?
About 1.34102 mechanical horsepower.
How many BTU per hour is 1 kilowatt?
About 3,412.14 BTU per hour.
What is the difference between watts and kilowatts?
A kilowatt is 1,000 watts. Watts suit small devices; kilowatts suit appliances and larger loads.
Is horsepower here mechanical or metric?
Mechanical horsepower, equal to 745.699872 watts.
How do I convert BTU per hour to watts?
Multiply the BTU per hour value by 0.29307107.
What is a foot-pound per second?
A unit of power equal to 1.35581795 watts, used mainly in older mechanical contexts.
