Power Converter - Watts, Horsepower, BTU/hr & More
Convert power between watts, kilowatts, megawatts, horsepower (mechanical & metric), BTU/hr, foot-pounds/min, and calories/sec.
Converted Values
Watts (W)
1,000
Megawatts (MW)
0.001
Horsepower - Mechanical (hp)
1.341022
Horsepower - Metric (PS)
1.359622
BTU per Hour (BTU/hr)
3,412.141635
Foot-Pounds per Minute
44,253.728967
Calories per Second (cal/s)
239.005736
How to Convert Power Units
Power measures the rate at which energy is transferred or converted, and it's expressed in many different units depending on the field — watts and kilowatts for electrical devices, horsepower for engines, and BTU per hour for heating and cooling equipment. This converter uses watts as a common base unit: every input value is first converted to watts using its exact conversion factor, then converted from watts into every other supported unit at once.
Example
A 3 kW electric motor is equal to 3,000 W, about 4.02 mechanical horsepower (3,000 ÷ 745.7), and roughly 10,235 BTU/hr (3,000 ÷ 0.29307107). Enter 3 with kilowatts selected as the source unit to see all of these values calculated at once.
Common Use Cases
- Comparing an appliance's wattage rating to an engine's horsepower rating.
- Converting an air conditioner's BTU/hr rating to kilowatts for energy calculations.
- Translating specification sheets between metric (kW, PS) and imperial (hp) power units.
- Estimating electrical load in watts from a generator or motor rated in horsepower.
FAQs
What is the difference between mechanical and metric horsepower?
Mechanical horsepower (used in the US and UK) equals 745.699872 watts, while metric horsepower (PS, common in Europe) equals 735.49875 watts. They are close but not identical, so this converter treats them as separate units.
Why is watts used as the base unit?
Watts is the SI unit of power, and every other unit here has a precisely defined conversion factor into watts. Converting everything to watts first, then out to each target unit, keeps the math consistent and avoids compounding rounding errors from unit-to-unit conversion tables.
How accurate are these conversions?
The conversion factors used are the standard internationally recognized values (for example, 1 mechanical horsepower = 745.699872 W exactly), so results are accurate to the number of decimal places shown.