training specialists to the upstream oil and gas industry


Insert the value you would like to convert into the relevant unit.

If there are any units that you would like included please get in touch with

Btu (IT) [Btu (IT), Btu]:
Btu (th) [Btu (th)]:
calorie (IT) [cal (IT), cal]:
calorie (nutritional):
calorie (th) [cal (th)]:
dyne centimeter [dyn*cm]:
electron-volt [eV]:
foot-pound [ft*lbf]:
fuel oil equivalent @kiloliter:
gigajoule [GJ]:
gigaton [Gton]:
gigawatt-hour [GW*h]:
gram-force centimeter:
gram-force meter [gf*m]:
horsepower (metric) hour:
horsepower hour [hp*h]:
inch-ounce [in*ozf]:
inch-pound [in*lbf]:
joule [J]:
kilocalorie (IT) [kcal (IT)]:
kilocalorie (th) [kcal (th)]:
kiloelectron-volt [keV]:
kilogram-force centimeter:
kilogram-force meter:
kilojoule [kJ]:
kiloton [kton]:
kilowatt-hour [kW*h]:
kilowatt-second [kW*s]:
mega Btu (IT) [MBtu (IT)]:
megaelectron-volt [MeV]:
megajoule [MJ]:
megaton [Mton]:
megawatt-hour [MW*h]:
microjoule [µJ]:
millijoule [mJ]:
nanojoule [nJ]:
newton meter [N*m]:
ounce-force inch [ozf*in]:
pound-force foot [lbf*ft]:
pound-force inch [lbf*in]:
poundal foot [pdl*ft]:
therm (EC):
therm (US):
ton (explosives):
ton-hour (refrigeration):
watt-hour [W*h]:
watt-second [W*s]: - the ultimate unit conversion resource.

Energy - Definition:
The capacity for doing work. Energy can exist in the following forms: radiation; kinetic energy; potential energy; chemical energy; atomic energy; electromagnetic energy; electrical energy; and heat energy. N m = kg m2 s-2 = CV = V A s = W s = J (Joule).

There can be some confusion in some of the units of energy. The calorie can take 5 different values and, while these do not vary by very much, for accurate work it is necessary to specify which calorie is being used. The 5 calories are known as the:

  • International Table calorie = cal(IT) = 4.1868 J
  • thermochemical calorie = cal(th) = 4.184 J
  • mean calorie = cal(mean) = 4.190 02 J
  • 15 degree C calorie = cal(15C) = 4.185 80 J
  • 20 degree C calorie = cal(20C) = 4.181 90 J.

Unless a clear statement is made saying otherwise, assume the IT calorie is being used.A further complication, in working with food and expressing nutritional values, the unit of a Calorie (capital C) is often used to represent 1000 calories, and again it is necessary to specify which calorie is being used for that. 

The British thermal unit (Btu) can also take different values and they are named in a similar way to the calorie. 

Also, note that the therm is 100 000 Btu so its exact size depends on which Btu is being used.
British thermal units:

  • Btu(IT) = 1055.056 J
  • Btu (th) = 1054.350 J
  • Btu (mean) = 1055.87J





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