Power Converter

Convert between watts, kilowatts, megawatts, horsepower (mechanical & electrical), BTU/hour, and foot-pounds per second.

Common Power Conversions
FromToResult
1 kWHorsepower (mech)1.34102 hp
1 hp (mech)Watts745.7 W
1 kWBTU/hr3,412.14 BTU/hr
1 MWkW1,000 kW
100 Whp (mech)0.134102 hp
1 GWMW1,000 MW
1 BTU/hrWatts0.293071 W
1 hp (elec)Watts746 W

Frequently Asked Questions

A watt (W) is the SI unit of power, defined as one joule per second (1 J/s). It measures the rate of energy transfer. A 100W light bulb consumes 100 joules per second. The watt is named after James Watt, the engineer who improved the steam engine.

Mechanical (imperial) horsepower = 745.69987 W, defined by James Watt based on a horse's power output. Electrical horsepower = 746 W exactly, used for electric motors. The difference is small (~0.04%) but matters for precise engineering calculations. Car engine ratings use mechanical hp.

One gigawatt = 1,000,000,000 watts (10⁹ W). A typical nuclear power plant generates about 1 GW. The famous "1.21 gigawatts" from Back to the Future is the power needed by the DeLorean's flux capacitor. The total electricity capacity of the US is around 1,200 GW.

BTU/hour is a US unit of power used primarily for heating and cooling equipment — air conditioners, furnaces, and heat pumps are rated in BTU/hr. 1 BTU/hr = 0.293071 W. A typical home air conditioner might be rated at 12,000 BTU/hr (1 "ton" of cooling = 12,000 BTU/hr ≈ 3.52 kW).

How It Works

Enter Power

Type any power value. The watt (W) is the SI base unit used internally for all conversions.

Choose Units

Select from metric (W/kW/MW/GW), imperial (hp, BTU/hr, ft·lb/s), and electrical horsepower units.

Get Result

Instant conversion with the exact factor used. Swap units and reference the table for quick comparisons.

Common Use Cases

Engine & Vehicle Power

Convert car engine ratings between horsepower and kilowatts to compare vehicles across US and European specifications.

HVAC & Home Appliances

Convert air conditioner and heater ratings between BTU/hr and kW for international comparisons and energy consumption calculations.

Solar & Renewable

Convert solar panel output and wind turbine capacity between W, kW, and MW for energy system design and comparison.

Electronics & Computing

Understand power supply ratings, processor TDP, and device consumption between watts and kilowatts for system design and billing.

Industrial Machinery

Convert motor and pump power ratings between horsepower and kW for procurement, motor selection, and international engineering specs.

Physics Education

Verify power unit conversions for mechanics problems, thermodynamics assignments, and engineering exam preparation.

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