 Online Calculators

Energy Conversion Calculator

Convert Energy

a real number or scientific notation

Calculator Use

Convert units of energy by entering the amount of energy and selecting the units you have, and the units you want to convert to.

• (IT) = International Table
• (th) = Thermochemical

How to Convert Units of Energy

Conversions are performed by using a conversion factor. By knowing the conversion factor, converting between units can become a simple multiplication problem:

S * C = E

Where S is our starting value, C is our conversion factor, and E is our end converted result.

To simply convert from any unit into joules, for example, from 100 kilowat-hours, just multiply by the conversion value in the right column in the table below.

100 kW · h * 3600000 [ (J) / ( kW · h) ] = 360000000 J

To convert from J into units in the left column divide by the value in the right column or, multiply by the reciprocal, 1/x.

360000000 J / 3600000  [ (J) / ( kW · h) ] = 100 kW · h

To convert among any units in the left column, say from A to B, you can multiply by the factor for A to convert A into Joules then divide by the factor for B to convert out of Joules.  Or, you can find the single factor you need by dividing the A factor by the B factor.

For example, to convert from kilowat-hours to British Thermal Units you would multiply by 3600000 then divide by 1055.056.  Or, multiply by 3600000/1055.056 = 3412.141156488. So, to convert directly from kW · h to BTU you multiply by 3412.141156488.

Units, symbols and conversion values
used in this energy calculator
To Convert from
Unit
Unit
Symbol
and Convert to
( J )
Multiply by
( J / Unit )
British thermal unit [IT]
BTUIT
joule
1055.056
British thermal unit [th]
BTUth
joule
1054.35
British thermal unit [mean]
BTUmean
joule
1055.87
British thermal unit [39°F]
BTU39°F
joule
1059.67
British thermal unit [59°F]
BTU59°F
joule
1054.8
British thermal unit [60°F]
BTU60°F
joule
1054.68
calorie [IT]
calIT
joule
4.1868
calorie [th]
calth
joule
4.184
calorie [mean]
calmean
joule
4.19002
calorie [15°C]
cal15°C
joule
4.1858
calorie [20°C]
cal20°C
joule
4.1819
electronvolt
eV
joule
1.60218E-19
erg
erg
joule
0.0000001
foot-poundal
ft·pdl
joule
0.04214011
foot-pound-force
ft·lbf
joule
1.355818
inch-pound-force
in·lbf
joule
0.112984829
joule
J
joule
1
megajoule
MJ
joule
1000000
kilocalorie [IT]
kcalIT
joule
4186.8
kilocalorie [th]
kcalth
joule
4184
kilocalorie [mean]
kcalmean
joule
4190.02
kilowatt-hour
kW·h
joule
3600000
joule
1.05506E+18
therm (EC)
therm
joule
105506000
therm (U.S.)
therm
joule
105480400
ton-of-coal-equivalent
TOC
joule
29307600000
ton-of-oil-equivalent
TOE
joule
41868000000
ton-of-TNT-equivalent
tTNT
joule
4184000000
watt-hour
W·h
joule
3600
watt-second
W·s
joule
1

The National Institute of Standards and Technology (NIST) - The NIST Guide for the use of the International System of Units - Appendix B, subsections B.8 Factors for Units Listed Alphabetically and B.9 Factors for units listed by kind of quantity or field of science.

Lide, David R., Daniel (Editor-in-Chief). CRC Handbook of Chemistry and Physics, 89th Edition New York, NY: CRC Press, p. 1-28, 2008.

Wikipedia contributors. "Conversion of units" Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, last visited 26 Jun. 2011.

How Many? A dictionary of units of measurement at http://www.unc.edu/~rowlett/units/

Cite this content, page or calculator as:

Furey, Edward "Energy Conversion Calculator" at https://www.calculatorsoup.com/calculators/conversions/energy.php from CalculatorSoup, https://www.calculatorsoup.com - Online Calculators