Convert Calories to British Thermal Units

Enter the energy in calories below to get the value converted to british thermal units.

Results in British Thermal Units:
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1 cal = 0.003966 BTU

How to Convert Calories to British Thermal Units

To convert a calorie measurement to a british thermal unit measurement, multiply the energy by the conversion ratio. One calorie is equal to 0.003966 british thermal units, so use this simple formula to convert:

british thermal units = calories × 0.003966

The energy in british thermal units is equal to the calories multiplied by 0.003966.

For example, here's how to convert 5 calories to british thermal units using the formula above.
5 cal = (5 × 0.003966) = 0.019828 BTU

Calories and british thermal units are both units used to measure energy. Keep reading to learn more about each unit of measure.


One calorie is equal to the heat needed to raise the temperature of one gram of water from 14.5 to 15.5 degrees Celsius.

When measuring the energy content in foods, the large calorie, or kilocalorie is used, but it's often still just called a "calorie." When both the calorie and large calorie are used in the same context it is common to refer to the calorie as a "small calorie."

Calories can be abbreviated as cal, for example 1 calorie can be written as 1 cal.

British Thermal Units

British thermal units are a measure of heat energy. Specifically, one british thermal unit is equal to the amount of heat energy required to increase the temperature of one pound of water one degree Fahrenheit. They are often used as a way to rate the energy heat producing appliances such furnaces, and to price heating fuels such as natural gas.

The british thermal unit is a US customary unit of energy. British thermal units can be abbreviated as BTU, for example 1 british thermal unit can be written as 1 BTU.

Calorie Measurements and Equivalent British Thermal Unit Conversions

Common calorie values converted to the equivalent british thermal unit value
Calories British Thermal Units
1 cal 0.003966 BTU
2 cal 0.007931 BTU
3 cal 0.011897 BTU
4 cal 0.015863 BTU
5 cal 0.019828 BTU
6 cal 0.023794 BTU
7 cal 0.02776 BTU
8 cal 0.031725 BTU
9 cal 0.035691 BTU
10 cal 0.039657 BTU
11 cal 0.043622 BTU
12 cal 0.047588 BTU
13 cal 0.051554 BTU
14 cal 0.055519 BTU
15 cal 0.059485 BTU
16 cal 0.063451 BTU
17 cal 0.067416 BTU
18 cal 0.071382 BTU
19 cal 0.075348 BTU
20 cal 0.079313 BTU
21 cal 0.083279 BTU
22 cal 0.087245 BTU
23 cal 0.09121 BTU
24 cal 0.095176 BTU
25 cal 0.099142 BTU
26 cal 0.103107 BTU
27 cal 0.107073 BTU
28 cal 0.111039 BTU
29 cal 0.115004 BTU
30 cal 0.11897 BTU
31 cal 0.122936 BTU
32 cal 0.126901 BTU
33 cal 0.130867 BTU
34 cal 0.134833 BTU
35 cal 0.138798 BTU
36 cal 0.142764 BTU
37 cal 0.14673 BTU
38 cal 0.150695 BTU
39 cal 0.154661 BTU
40 cal 0.158627 BTU

More Calorie Energy Conversions

Convert to Joules
1 cal is equal to 4.184 joules
Convert to Kilojoules
1 cal is equal to 0.004184 kilojoules
Convert to Megajoules
1 cal is equal to 4.184E-6 megajoules
Convert to Gigajoules
1 cal is equal to 4.184E-9 gigajoules
Convert to Kilocalories
1 cal is equal to 0.001 kilocalories
Convert to Megacalories
1 cal is equal to 1.0E-6 megacalories
Watts x Time
Convert to Watt-hours
1 cal is equal to 0.001162 watt-hours
Convert to Kilowatt-hours
1 cal is equal to 1.1622E-6 kilowatt-hours
Convert to Megawatt-hours
1 cal is equal to 1.1622E-9 megawatt-hours
Convert to Watt-seconds
1 cal is equal to 4.184 watt-seconds
Thermal Units
Convert to Million BTU
1 cal is equal to 3.9657E-9 million BTU
Convert to Therms
1 cal is equal to 3.9657E-8 therms
Convert to Quads
1 cal is equal to 3.9657E-18 quads
Convert to Electronvolts
1 cal is equal to 26,114,000,000,000,000,000 electronvolts
Convert to Kiloelectronvolts
1 cal is equal to 26,114,000,000,000,000 kiloelectronvolts
Convert to Megaelectronvolts
1 cal is equal to 26,114,475,092,200.6 megaelectronvolts