Energy Calculators

From gallons to British thermal units (Btu), kilowatthours to megajoules, short tons to metric tons, this handy calculator converts from one energy unit to another.

Calculators for energy used in the United States

• Coal
• Electricity
• Natural gas
• Crude oil
• Gasoline
• Diesel fuel and heating oil
• Measuring energy in food—food calories versus energy calories
• Scientific notation explained—E+10

Note: Btu is British thermal units.

Coal conversion calculator

short tons Btu megajoules metric tons

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1 short ton = 18,875,000 Btu (based on U.S. electric power sector consumption in 2019; preliminary)

Electricity conversion calculator

kilowatthours Btu megajoules million calories

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1 kilowatthour = 3,412 Btu (standard conversion factor)

Natural gas conversion calculator

cubic feet Btu megajoules cubic meters

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1 cubic foot = 1,037 Btu (based on U.S. average for natural gas delivered to consumers in 2019, preliminary)

Crude oil conversion calculator

barrels Btu megajoules liters

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1 barrel = 42 U.S. gallons = 5,698,000 Btu (based on U.S. production in 2019, preliminary)

Gasoline conversion calculator

gallons Btu megajoules liters

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1 gallon = 120,286 Btu (based on U.S. finished motor gasoline consumption in 2019, including fuel ethanol content; preliminary)

Diesel fuel and heating oil conversion calculator

gallons Btu megajoules liters

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1 gallon = 137,381 Btu (for distillate fuel with 15 ppm or less sulfur content)

Measuring energy in food

Food calories are a measure of energy in food. One food calorie is equal to 1,000 calories, or 1 kilocalorie. For example, the energy in a 300-food calorie ice cream cone is about the same as the amount of electricity required to light a 100-watt incandescent light bulb for 3.5 hours.

Food energy conversion calculator

food calories Btu megajoules kilowatthours

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1 food calorie = 1,000 calories, or 1 kilocalorie, or 3.9683 Btu

Scientific notation explained

Scientific notation is a short-hand way of writing a number that has a lot of digits. For example, the number 525,000,000 could be written as 5.25E+08. The +08 indicates the decimal should be moved eight places to the right. A negative number after the E means the decimal should be moved a certain number of places to the left. For example, 5.25E-03 is the same as 0.00525.