Convert Calories to British Thermal Units
cal to BTU · energy conversion
What are calories and british thermal units?
A small calorie is the energy to heat one gram of water by 1 °C, about 4.184 J. A British thermal unit is the energy to heat one pound of water by 1 °F, used for heating and AC. For reference: a food Calorie is one kilocalorie (4,184 J), and home electricity is billed in kilowatt-hours.
How to convert calories to british thermal units
1 cal = 0.00396567 BTU. To convert, multiply the number of calories by 0.00396567. For example, 5 cal = 0.0198283 BTU, and 20 cal = 0.0793133 BTU. To go the other way, multiply british thermal units by 252.164 (since 1 BTU = 252.164 cal).
Calories to British Thermal Units conversion table
| Calories (cal) | British Thermal Units (BTU) |
|---|---|
| 1 | 0.00396567 |
| 10 | 0.0396567 |
| 100 | 0.396567 |
| 500 | 1.98283 |
| 1,000 | 3.96567 |
| 2,000 | 7.93133 |
| 5,000 | 19.8283 |
FAQ
What is 1 cal in BTU?
1 cal = 0.00396567 BTU. To convert any amount, multiply the number of calories by 0.00396567.
How do I convert british thermal units back to calories?
Go the other way: 1 BTU = 252.164 cal, so multiply british thermal units by 252.164 to get calories.
Is a calorie bigger than a british thermal unit?
No — 1 cal is the smaller unit, equal to 0.00396567 BTU (it takes 252.164 cal to make one BTU).
Are these energy conversions exact?
They use the standard internationally-defined conversion factors. Results are rounded to six significant figures for readability, which is accurate enough for everyday and most technical use.