Convert BTU to Calories
Convert BTU to Calories instantly. 1 BTU (BTU) equals 252.1644 Calories (cal).
BTU to Calories conversion table
| BTU (BTU) | Calories (cal) |
|---|---|
| 1 BTU | 252.1644 cal |
| 2 BTU | 504.3288 cal |
| 3 BTU | 756.4932 cal |
| 5 BTU | 1,260.82 cal |
| 10 BTU | 2,521.64 cal |
| 20 BTU | 5,043.29 cal |
| 50 BTU | 12,608.22 cal |
| 100 BTU | 25,216.44 cal |
| 500 BTU | 126,082.2 cal |
| 1,000 BTU | 252,164.4 cal |
1 BTU = 252.1644 Calories · multiply BTU by 252.1644
About converting BTU to Calories
BTU (BTU) and Calories (cal) are both units of energy, so converting between them is a single multiplication: multiply your BTU figure by 252.1644. Ten BTU comes to 2,521.64 Calories, and a hundred works out at 25,216.44 Calories.
Rule of thumb: going from BTU to Calories multiplies, so the figure always grows — one BTU is already 252.1644 Calories. If your answer came out smaller, you have the conversion the wrong way round.
What is a BTU?
The BTU is the heat needed to raise one pound of water by one degree Fahrenheit — and there is no single BTU. Water takes slightly different amounts of heat to warm depending on the temperature it starts from, so several definitions exist (thermochemical, International Table, 39 °F, 59 °F, 60 °F and others), differing from one another by a fraction of a percent. This converter uses one common value, so treat the result as convention-dependent rather than absolute. In the US it is the unit of heating and cooling capacity, though air conditioners are really rated in BTU per hour and the "per hour" is routinely dropped in marketing.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.
To put both in perspective: a wooden kitchen match releases roughly one BTU, while an apple holds roughly 95,000 small calories.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Calories to BTU converter, or browse all Energy converters.
Frequently asked questions
How many Calories are in one BTU?
There are 252.1644 Calories in one BTU.
How do I convert BTU to Calories?
Multiply the number of BTU by 252.1644. For example, 10 BTU = 2,521.64 Calories.
What is 100 BTU in Calories?
100 BTU is equal to 25,216.44 Calories.
How do I convert Calories to BTU?
Multiply the Calories value by 0.003966 (or divide by 252.1644).
Is this BTU to Calories conversion exact?
The figure is accurate to the precision shown. 1 BTU = 252.1644 Calories is rounded for readability, so for engineering or scientific work carry more decimal places than the table displays.
What is a BTU?
The BTU is the heat needed to raise one pound of water by one degree Fahrenheit — and there is no single BTU. Water takes slightly different amounts of heat to warm depending on the temperature it starts from, so several definitions exist (thermochemical, International Table, 39 °F, 59 °F, 60 °F and others), differing from one another by a fraction of a percent. This converter uses one common value, so treat the result as convention-dependent rather than absolute. In the US it is the unit of heating and cooling capacity, though air conditioners are really rated in BTU per hour and the "per hour" is routinely dropped in marketing.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.