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Guide

How to Convert Between Power Units (watts, kilowatts, horsepower)

Learn the common power units, how they relate, and how to convert between them for engineering and appliances.

Open the Power Converter

A power converter translates values between watts, kilowatts, megawatts, horsepower, BTU per hour, and foot-pounds per second. Power is the rate of energy use, and different fields use different units.

Common power units

  • Watt (W) — the SI unit of power.
  • Kilowatt (kW) and megawatt (MW) — 1000 W and 1,000,000 W.
  • Horsepower (hp) — about 745.7 W; common for engines and motors.
  • BTU/hour — heat output, common in HVAC.
  • Foot-pounds per second — mechanical power.

Key conversion factors

  • 1 hp ≈ 745.7 W = 0.7457 kW.
  • 1 kW = 1000 W ≈ 1.341 hp.
  • 1 BTU/h ≈ 0.2931 W.
  • 1 kW ≈ 3412 BTU/h.

How to use the converter

  1. Enter a value and choose its unit.
  2. Choose the target unit.
  3. Read the converted power.

Examples

A 150 hp car engine produces about 111.9 kW. A 2000 W heater outputs about 6824 BTU/h. A 12,000 BTU/h air conditioner draws about 3.52 kW.

When a power converter is useful

  • Comparing appliance or motor ratings.
  • Sizing heating, cooling, or generators.
  • Converting engineering specs across unit systems.
  • Estimating electricity use from power ratings.

Put it into practice

Use the Power Converter right now — free, in your browser, no sign-up required.

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