Calories to British Thermal Units Conversion

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.

Since one calorie is equal to 0.003966 british thermal units, you can 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 500 calories to british thermal units using the formula above.
500 cal = (500 × 0.003966) = 1.982833 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 to British Thermal Unit Conversion Table

Calorie measurements converted to british thermal units
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
20 cal 0.079313 BTU
30 cal 0.11897 BTU
40 cal 0.158627 BTU
50 cal 0.198283 BTU
60 cal 0.23794 BTU
70 cal 0.277597 BTU
80 cal 0.317253 BTU
90 cal 0.35691 BTU
100 cal 0.396567 BTU
200 cal 0.793133 BTU
300 cal 1.1897 BTU
400 cal 1.5863 BTU
500 cal 1.9828 BTU
600 cal 2.3794 BTU
700 cal 2.776 BTU
800 cal 3.1725 BTU
900 cal 3.5691 BTU
1,000 cal 3.9657 BTU