Kilocalorie to British Thermal Unit Converter
One Kilocalorie equals 3.965666831 British Thermal Unit (1 kcal = 3.965666831 BTU). Multiply a Kilocalorie value by 3.965666831 to get the equivalent in British Thermal Unit. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
BTU = kcal × 3.965666831
Multiply the Kilocalorie value by 3.965666831 to get the equivalent value in British Thermal Unit.
Example Conversions
1 Kilocalorie (kcal)
3.965666831 British Thermal Unit (BTU)
5 Kilocalorie (kcal)
19.82833416 British Thermal Unit (BTU)
10 Kilocalorie (kcal)
39.65666831 British Thermal Unit (BTU)
25 Kilocalorie (kcal)
99.14167078 British Thermal Unit (BTU)
100 Kilocalorie (kcal)
396.5666831 British Thermal Unit (BTU)
Conversion Table
| Kilocalorie (kcal) | British Thermal Unit (BTU) |
|---|---|
| 0.1 | 0.3965666831 |
| 0.5 | 1.982833416 |
| 1 | 3.965666831 |
| 2 | 7.931333663 |
| 5 | 19.82833416 |
| 10 | 39.65666831 |
| 25 | 99.14167078 |
| 50 | 198.2833416 |
| 100 | 396.5666831 |
| 250 | 991.4167078 |
| 500 | 1982.833416 |
| 1000 | 3965.666831 |
How to Convert Manually
Use these steps to convert Kilocalorie values to British Thermal Unit without the calculator.
- Write down the value in Kilocalorie (kcal) that you want to convert.
- Multiply that value by 3.965666831.
- For example, 10 Kilocalorie × 3.965666831 = 39.65666831 British Thermal Unit.
- Label the result as British Thermal Unit (BTU).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Kilocalorie and one British Thermal Unit.
About Kilocalorie and British Thermal Unit
The kilocalorie is 4,184 joules — the food 'Calorie' (capital C) on US nutrition labels. Diet tracking and exercise burn estimates use kilocalories. The British thermal unit is about 1,055.06 joules — the heat to raise one pound of water by 1 °F. US heating and cooling equipment is rated in BTU per hour. One Kilocalorie equals 3.965666831 British Thermal Unit (1 kcal = 3.965666831 BTU). Kilocalorie to British Thermal Unit conversion comes up most often in nutrition labels and diet tracking and in exercise calorie burn, typically when figures need restating for air conditioner and furnace ratings in the US.
Precision and Rounding: Energy factors mix exact definitions (1 kWh = 3,600,000 J; 1 cal = 4.184 J thermochemical) with measured conventions (1 BTU ≈ 1,055.056 J). Nutrition and utility bills round to whole units; engineering heat calculations should keep the full factor until the final step.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Kilocalorie equals 59.48500247 British Thermal Unit.
15 kcal × 3.965666831 = 59.48500247 BTU
FAQ
How do I convert Kilocalorie to British Thermal Unit?
Multiply the Kilocalorie value by 3.965666831 to get the equivalent value in British Thermal Unit.
What is the formula for Kilocalorie to British Thermal Unit?
The formula is BTU = kcal × 3.965666831.
How many British Thermal Unit are in 1 Kilocalorie?
1 Kilocalorie equals 3.965666831 British Thermal Unit.
Can I convert British Thermal Unit back to Kilocalorie?
Yes. 1 British Thermal Unit equals 0.2521644007 Kilocalorie, and the related converter can reverse the calculation.
What are common names for Kilocalorie and British Thermal Unit?
Kilocalorie is shown as kcal and may also be searched as kilocalorie, kilocalories, food calorie. British Thermal Unit is shown as BTU and may also be searched as btu, british thermal unit.
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