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Power units converter. This calculator converts between horsepower, wats and over a dozen other power units.
Some facts
  • Power determines the work done by a physical system in given time unit.
  • Power is a scalar. It means that it has no direction.
  • Basic power unit in SI system is 1W (one watt). Power has 1W value, when system done work 1 joule in time of 1 second.
  • The instantaneous power is defined as a derivative of work dW/dt.
  • To calculate the average power over a period of time <t0, t1>, we need to compute integral Pavg. = 1/(t1-t0) · ∫p(t)dt.
  • If work is constant (time independent), we can compute average power in simpler way using formula: Pavg.=W/t, where W is work and t is time.
  • The power consumed by the electric device can be calculated using the formula: P=U·I, where U is the voltage and I the intensity of the electric current. This property is used, eg. by popular power meters available on the market, which measure the electric power consumed by the device.
  • In alternative way, power can be understood as speed of energy emission.
  • If certain electric device charge e.g. 60W of power, then the same amount of power is emitted to the outside. This follows from the principle of conservation of energy. Almost all energy consumed by electrical devices is emitted as heat. This problem has become particularly noticeable with the rapid development of computers. In the early 90s processors found in personal computers do not required special cooling. Beggining from 586 (Pentium), the CPU fan has become an integral part of any personal computer.
How to convert?
  • Enter the number to field "value" - enter the NUMBER only, no other words, symbols or unit names. You can use dot (.) or comma (,) to enter fractions.
    • 1000000
    • 123,23
    • 999.99999
  • Find and select your starting unit in field "unit". Some unit calculators have huge number of different units to select from - it's just how complicated our world is...
  • And... you got the result in the table below. You'll find several results for many different units - we show you all results we know at once. Just find the one you're looking for.
value: unit: decimals:


milliwatt [mW]
wat [W]
joule per second [W]
kilowatt [kW]
megawatt [MW]
gigawatt [GW]

horse power

horsepower (metric) [hp]
horsepower (mechanical) [hp]
horsepower (electrical) [hp]
boiler horsepower


foot-pound-force per hour [ft lbf/h]
foot-pound-force per minute [ft lbf/min]
foot-pound-force per second [ft lbf/s]
atmosphere cubic foot per hour [atm·cfh]
atmosphere cubic foot per minute [atm·cfm]
atmosphere cubic foot per second [atm·cfs]


atmosphere cubic centimetre per hour [atm cch]
atmosphere cubic centimetre per minute [atm ccm]
atmosphere cubic centimetre per second [atm ccs]
litre-atmosphere per hour [L·atm/h]
litre-atmosphere per minute [L·atm/min]
litre-atmosphere per second [L·atm/s]
poncelet [p]


BTUIT per hour [BTUIT/h]
BTUIT per minute [BTUIT/min]
BTUIT per second [BTUIT/s]


calorie (International Table) per hour [calIT/h]
calorie (International Table) per minute [calIT/m]
calorie (International Table) per second [calIT/s]
lusec [L·µmHg/s]
square foot equivalent direct radiation [sq ft EDR]
ton of air conditioning
ton of refrigeration (IT)
ton of refrigeration (Imperial)
power · horsepower · watt

Tags to Polish version:
moc · wat · kon_mechaniczny