Convert British thermal units to Kilocalories
1 British thermal unit is 0.252164 kcal. One British thermal unit is exactly 0.252164400722 kilocalories.
One British thermal unit is 0.2521644 kilocalories. To convert British thermal units to kilocalories, multiply by 0.2521644; to go the other way, divide by 0.2521644 or multiply by 3.9656668. The factor is exact rather than rounded: it follows from NIST Special Publication 811. The international-table BTU, fixed at exactly 1055.05585262 joules.
Factor checked against the defining standard · How we check
- British thermal units × 0.2521644
value * 0.2521644007220.252 kcal
1 British thermal unit in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 1,055.055853 J | × 1,055.05585262 |
| kilojoules | 1.055055853 kJ | × 1.05505585262 |
| calories | 252.1644007 cal | × 252.164400722 |
| kilocalories | 0.2521644007 kcal | × 0.252164400722 |
| watt-hours | 0.2930710702 Wh | × 0.293071070172 |
| kilowatt-hours | 0.0002930710702 kWh | × 0.000293071070172 |
| British thermal units (as entered) | 1 BTU | — |
| foot-pounds | 778.1692623 ft·lbf | × 778.169262266 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert British thermal units to kilocalories?
- 1.Take the measurement in British thermal units.
- 2.Multiply by 0.2521644 — that is how many kilocalories fit in one British thermal unit.
- 3.To go back the other way, divide by 0.2521644, or multiply by 3.9656668.
Worked example: 25 British thermal units to kilocalories
- Formula
- BTU × 0.2521644 = kcal
- Arithmetic
- 25 × 0.2521644 = 6.30411 kcal
- Answer
- 25 BTU = 6.30411 kcal
The factor is rounded for display; the figure above is computed from the full value.
British thermal units to kilocalories conversion table
| British thermal units | Kilocalories |
|---|---|
| 1 BTU | 0.252164 kcal |
| 2 BTU | 0.504329 kcal |
| 3 BTU | 0.756493 kcal |
| 4 BTU | 1.008658 kcal |
| 5 BTU | 1.260822 kcal |
| 6 BTU | 1.512986 kcal |
| 7 BTU | 1.765151 kcal |
| 8 BTU | 2.017315 kcal |
| 9 BTU | 2.26948 kcal |
| 10 BTU | 2.521644 kcal |
| 12 BTU | 3.025973 kcal |
| 15 BTU | 3.782466 kcal |
| 20 BTU | 5.043288 kcal |
| 25 BTU | 6.30411 kcal |
| 50 BTU | 12.60822 kcal |
| 100 BTU | 25.21644 kcal |
| 200 BTU | 50.43288 kcal |
| 300 BTU | 75.64932 kcal |
| 500 BTU | 126.0822 kcal |
| 1000 BTU | 252.164401 kcal |
| 2000 BTU | 504.328801 kcal |
| 5000 BTU | 1,260.822004 kcal |
| 10000 BTU | 2,521.644007 kcal |
What is a British thermal unit?
The international-table BTU, fixed at exactly 1055.05585262 joules. Roughly the heat needed to raise a pound of water by one degree Fahrenheit, which is where it came from.
What is a kilocalorie?
A thousand small calories, and what a food label means by "Calories" with a capital C. A 2,000 calorie diet is 2,000 kcal, or 8.4 megajoules.
How many kilocalories are in a British thermal unit?
One British thermal unit is 0.2521644 kilocalories. Going the other way, one kilocalorie is 3.9656668 British thermal units. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every energy unit here
| Unit | Symbol | One of these is |
|---|---|---|
| Joules | J | the base unit |
| Kilojoules | kJ | 1000 joule |
| Calories | cal | 4.184 joule |
| Kilocalories | kcal | 4184 joule |
| Watt-hours | Wh | 3600 joule |
| Kilowatt-hours | kWh | 3600000 joule |
| British thermal units | BTU | 1055.0559 joule |
| Foot-pounds | ft·lbf | 1.3558179 joule |
Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J
Questions people actually ask
- How many kilocalories are in a British thermal unit?
- 0.2521644. A thousand small calories, and what a food label means by "Calories" with a capital C. A 2,000 calorie diet is 2,000 kcal, or 8.4 megajoules.
- How do I convert kilocalories back to British thermal units?
- Divide by 0.2521644, or multiply by 3.9656668 — they are the same operation.
Other energy conversions
Kilocalories to British thermal units — the same conversion the other way.