Convert Kilocalories to British thermal units
1 kilocalorie is 3.965667 BTU. One kilocalorie is exactly 3.96566683139 British thermal units.
One kilocalorie is 3.9656668 British thermal units. To convert kilocalories to British thermal units, multiply by 3.9656668; to go the other way, divide by 3.9656668 or multiply by 0.2521644. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousand small calories, and what a food label means by "Calories" with a capital C.
Factor checked against the defining standard · How we check
- Kilocalories × 3.9656668
value * 3.965666831393.966 BTU
1 kilocalorie in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 4,184 J | × 4,184 |
| kilojoules | 4.184 kJ | × 4.184 |
| calories | 1,000 cal | × 1,000 |
| kilocalories (as entered) | 1 kcal | — |
| watt-hours | 1.162222222 Wh | × 1.16222222222 |
| kilowatt-hours | 0.001162222222 kWh | × 0.00116222222222 |
| British thermal units | 3.965666831 BTU | × 3.96566683139 |
| foot-pounds | 3,085.960033 ft·lbf | × 3,085.96003258 |
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 kilocalories to British thermal units?
- 1.Take the measurement in kilocalories.
- 2.Multiply by 3.9656668 — that is how many British thermal units fit in one kilocalorie.
- 3.To go back the other way, divide by 3.9656668, or multiply by 0.2521644.
Worked example: 25 kilocalories to British thermal units
- Formula
- kcal × 3.9656668 = BTU
- Arithmetic
- 25 × 3.9656668 = 99.141671 BTU
- Answer
- 25 kcal = 99.141671 BTU
The factor is rounded for display; the figure above is computed from the full value.
Kilocalories to British thermal units conversion table
| Kilocalories | British thermal units |
|---|---|
| 1 kcal | 3.965667 BTU |
| 2 kcal | 7.931334 BTU |
| 3 kcal | 11.897 BTU |
| 4 kcal | 15.862667 BTU |
| 5 kcal | 19.828334 BTU |
| 6 kcal | 23.794001 BTU |
| 7 kcal | 27.759668 BTU |
| 8 kcal | 31.725335 BTU |
| 9 kcal | 35.691001 BTU |
| 10 kcal | 39.656668 BTU |
| 12 kcal | 47.588002 BTU |
| 15 kcal | 59.485002 BTU |
| 20 kcal | 79.313337 BTU |
| 25 kcal | 99.141671 BTU |
| 50 kcal | 198.283342 BTU |
| 100 kcal | 396.566683 BTU |
| 200 kcal | 793.133366 BTU |
| 300 kcal | 1,189.700049 BTU |
| 500 kcal | 1,982.833416 BTU |
| 1000 kcal | 3,965.666831 BTU |
| 2000 kcal | 7,931.333663 BTU |
| 5000 kcal | 19,828.334157 BTU |
| 10000 kcal | 39,656.668314 BTU |
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.
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.
How many British thermal units are in a kilocalorie?
One kilocalorie is 3.9656668 British thermal units. Going the other way, one British thermal unit is 0.2521644 kilocalories. 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 British thermal units are in a kilocalorie?
- 3.9656668. 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.
- How do I convert British thermal units back to kilocalories?
- Divide by 3.9656668, or multiply by 0.2521644 — they are the same operation.
Other energy conversions
British thermal units to kilocalories — the same conversion the other way.