Power Conversions

power conversions
Power Conversions - logo
Select a unit of power

What is power?

Definition: Power is the rate at which energy is transformed or work is done. The standard derived unit of power in the International System of Units (SI) is the watt (W). Other units of power commonly in use throughout the world include kilowatts (kW), megawatts (MW), gigawatts (GW), British thermal units per hour (BTU/h), Celsius heat units per hour (CHU/h), calories per hour (cal/h), calories per day (cal/d), kilocalories per hour (kcal/h), foot-pound-force per second ( ft lbf/s), inch-pound-force per second (in lbf/s), liter-atmosphere per second (L atm/s) and horsepower (hp).

Common power conversions

  • 1 watt (W) = 1,000 milliwatts (mW) = 1,000,000 microwatts (μW)
  • 1 kilowatt (kW) = 1,000 watts (W) = 1,000,000 milliwatts (mW)
  • 1 gigawatt (GW) = 1,000 kilowatts (kW) = 1,000,000 watts (W)
  • 1 horsepower (metric) (hp) = 735.49875 watts (W) = 0.73549875 kilowatts (kW)
  • 1 British thermal unit (IT) per hour (BTU/h) = 0.29307107 watts (W)
  • 1 British thermal unit (59 °F) per hour (BTU/h) = 0.293001111 watts (W)
  • 1 calorie (IT) per hour (cal/h) = 0.001163 watts (W)
  • 1 erg per second (erg/s) = 10-7 watts (W)
  • 1 foot-pound-force per second (ft lbf/s) = 1.355817948 watts (W)
  • 1 ton of refrigeration (IT) (RT) = 3,516.853 watts (W)

Subdivisions and multiples of the watt using SI prefixes

Subdivisions of the watt Multiples of the watt
Name Symbol Value Name Symbol Value
deciwatt dW 10-1 W decawatt daW 101 W
centiwatt cW 10-2 W hectowatt hW 102 W
milliwatt mW 10-3 W kilowatt kW 103 W
microwatt μW 10-6 W megawatt MW 106 W
nanowatt nW 10-9 W gigawatt GW 109 W
picowatt pW 10-12 W terawatt TW 1012 W
femtowatt fW 10-15 W petawatt PW 1015 W
attowatt aW 10-18 W exawatt EW 1018 W
zeptowatt zW 10-21 W zettawatt ZW 1021 W
yoctowatt yW 10-24 W yottawatt YW 1024 W

Below you can find a comprehensive list with conversions from and to various (metric, imperial, or customary) power measurement units.

  • convert from atmosphere-cubic centimeter per minute (atm ccm)
  • convert from atmosphere-cubic centimeter per second (atm ccs)
  • convert from BTU (IT) per hour (BTU/h)
  • convert from BTU (IT) per minute (BTU/min)
  • convert from BTU (IT) per second (BTU/s)
  • convert from calories per day (cal/d)
  • convert from calories per hour (cal/h)
  • convert from calories per minute (cal/min)
  • convert from calories per second (cal/s)
  • convert from Celsius heat units (IT) per hour (CHU/h)
  • convert from Celsius heat units (IT) per minute (CHU/min)
  • convert from Celsius heat units (IT) per second (CHU/s)
  • convert from cubic feet de natural gas per hour
  • convert from cubic feet de natural gas per minute
  • convert from cubic feet de natural gas per second
  • convert from ergs per hour (erg/h)
  • convert from ergs per minute (erg/min)
  • convert from ergs per second (erg/s)
  • convert from foot-pound-force per hour (ft lbf/h)
  • convert from foot-pound-force per minute (ft lbf/min)
  • convert from foot-pound-force per second (ft lbf/s)
  • convert from gigawatts (GW)
  • convert from horsepower (boiler) (hp)
  • convert from horsepower (electric) (hp)
  • convert from horsepower (hydraulic) (hp)
  • convert from horsepower (mechanical) (hp)
  • convert from horsepower (metric) (hp)
  • convert from kilocalories per day (kcal/d)
  • convert from kilocalories per hour (kcal/h)
  • convert from kilocalories per minute (kcal/min)
  • convert from kilocalories per second (kcal/s)
  • convert from kilowatts (kW)
  • convert from liter-atmosphere per minute (L atm/min)
  • convert from liter-atmosphere per second (L atm/s)
  • convert from lusec (lusec)
  • convert from megawatts (MW)
  • convert from microwatts (μW)
  • convert from milliwatts (mW)
  • convert from nanowatts (nW)
  • convert from poncelet (p)
  • convert from terawatts (TW)
  • convert from tons of air conditioning
  • convert from tons of refrigeration (IT) (TR)
  • convert from watts (W)