Power Converter

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

Value
From
To
1 Kilowatt = — Horsepower (mech)
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).
One mechanical horsepower = 745.7 watts. A 200 hp car engine produces about 149.1 kW. Electric motors are rated in kilowatts (kW). A 100 kW electric car motor equals about 134 hp. Horsepower is mainly used for vehicles and engines; watts and kilowatts are the SI standard for all other applications.
A kilowatt (kW) = 1,000 watts. A megawatt (MW) = 1,000 kW = 1,000,000 watts. A typical home uses 1–5 kW on average. A large wind turbine generates 2–5 MW. A nuclear power plant generates about 1,000 MW (1 GW). Power plants and grid capacity are measured in MW and GW.
A US home uses on average about 1.2 kW continuously (roughly 900 kWh per month). Peak demand can reach 5–10 kW when running large appliances simultaneously. Common loads: refrigerator (100–200 W), electric dryer (5,000 W), microwave (1,000 W), LED light bulb (10 W), central AC (3,000–5,000 W).
Watt (W) is a unit of power — the rate of energy use at any instant. Watt-hour (Wh) is a unit of energy — power used over time. A 100W bulb running for 10 hours uses 1,000 Wh = 1 kWh. Power is like speed (km/h); energy is like distance (km). You pay for energy (kWh) on electricity bills, not power.
Power is the rate at which energy is transferred or converted, measured in watts (W). Energy is the total amount transferred over time, measured in joules (J) or watt-hours (Wh). Power × Time = Energy. A sports car engine may have high power (500 kW) but a battery stores energy (100 kWh) — these are fundamentally different quantities.
Power factor (PF) is the ratio of real power (watts) to apparent power (volt-amperes, VA) in an AC circuit. A PF of 1.0 means all power is used productively; motors and fluorescent lights often have PF of 0.7–0.9. Utilities may charge industrial customers for low power factor. PF matters only in AC systems, not DC.

About This Power Converter

This free power converter converts between watts, kilowatts, megawatts, horsepower (mechanical and electrical), BTU per hour, and other power units. Enter a value in any unit for instant conversions.

When to use this converter

  • Comparing engine power in horsepower vs kilowatts
  • Calculating appliance or server power consumption
  • Converting electrical power ratings between standards
  • HVAC ratings between BTU/hr and kW

Standards & References

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