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Converting Energy Units 101           

Tons, barrels, cubic feet--how do you compare apples and oranges? To make meaningful comparisons of energy commodities, you must convert physical units of measure (such as weight or volume) and the energy content of each fuel to comparable units. One practical way to compare different fuels is to convert them into units of heat content, such as British thermal units (Btu), joules, or calories. The Btu is the measure of thermal energy used most frequently in the United States. The following factors may be used to convert U.S. thermal energy units to metric energy units (joules):

U.S. Units    
 
Equivalent Metric Units
1 British thermal unit (Btu)
 =   
1,055.05585262 joules (J)
1 calorie (cal)
 =   
4.1868 joules (J)
1 kilowatthour (kWh)
 =   
3.6 megajoules(MJ)

Not Just for Kids -- on the Energy Kid's Page
U.S. Energy Units Calculator - conversions for common energy units
British Thermal Units (Btu) - explanation and examples
How Big is a Barrel? - petroleum
Measuring Electricity
Measuring Natural Gas
Scientific Notation Explained - E + 10?

Factors for Converting Energy Units
General Conversion Factors - includes physical units per metric ton
Thermal Conversion Factors - Btu content of common U.S. units (barrel, cubic foot, short ton, etc.)
Thermal Conversion Factors - country specific factors
Units of Measure Equivalents - related to electricity

Overview Discussions
What Is a Btu?
How do I compare heating fuels? - get the answer
How many gallons of gasoline does one barrel of crude oil make? - get the answer

BTU Content of Common Energy Units

1 barrel (42 gallons) of crude oil = 5,800,000 Btu

1 gallon of gasoline = 124,000 Btu
(U.S. motor gasoline consumption in 2007)

1 gallon of heating oil or diesel fuel = 139,000 Btu

1 cubic foot of natural gas = 1,028 Btu
(U.S. natural gas consumption in 2007)

1 gallon of propane = 91,000 Btu

1 short ton of coal = 21,169,000 Btu
(U.S. coal consumption in 2007)

1 kilowatthour of electricity = 3,412 Btu


References
EIA Abbreviations
Energy Kid's Page
Frequently Asked Questions
A-Z Topics