British Thermal Unit to Kilocalorie Converter
One British Thermal Unit equals 0.2521644007 Kilocalorie (1 BTU = 0.2521644007 kcal). Multiply a British Thermal Unit value by 0.2521644007 to get the equivalent in Kilocalorie. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
kcal = BTU × 0.2521644007
Multiply the British Thermal Unit value by 0.2521644007 to get the equivalent value in Kilocalorie.
Example Conversions
1 British Thermal Unit (BTU)
0.2521644007 Kilocalorie (kcal)
5 British Thermal Unit (BTU)
1.260822004 Kilocalorie (kcal)
10 British Thermal Unit (BTU)
2.521644007 Kilocalorie (kcal)
25 British Thermal Unit (BTU)
6.304110018 Kilocalorie (kcal)
100 British Thermal Unit (BTU)
25.21644007 Kilocalorie (kcal)
Conversion Table
| British Thermal Unit (BTU) | Kilocalorie (kcal) |
|---|---|
| 0.1 | 0.02521644007 |
| 0.5 | 0.1260822004 |
| 1 | 0.2521644007 |
| 2 | 0.5043288014 |
| 5 | 1.260822004 |
| 10 | 2.521644007 |
| 25 | 6.304110018 |
| 50 | 12.60822004 |
| 100 | 25.21644007 |
| 250 | 63.04110018 |
| 500 | 126.0822004 |
| 1000 | 252.1644007 |
How to Convert Manually
Use these steps to convert British Thermal Unit values to Kilocalorie without the calculator.
- Write down the value in British Thermal Unit (BTU) that you want to convert.
- Multiply that value by 0.2521644007.
- For example, 10 British Thermal Unit × 0.2521644007 = 2.521644007 Kilocalorie.
- Label the result as Kilocalorie (kcal).
Relative Size Comparison
This chart shows the visual difference in size between exactly one British Thermal Unit and one Kilocalorie.
About British Thermal Unit and Kilocalorie
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. The kilocalorie is 4,184 joules — the food 'Calorie' (capital C) on US nutrition labels. Diet tracking and exercise burn estimates use kilocalories. One British Thermal Unit equals 0.2521644007 Kilocalorie (1 BTU = 0.2521644007 kcal). British Thermal Unit to Kilocalorie conversion comes up most often in air conditioner and furnace ratings in the US and in US natural gas appliance specs, typically when figures need restating for nutrition labels and diet tracking.
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 British Thermal Unit equals 3.782466011 Kilocalorie.
15 BTU × 0.2521644007 = 3.782466011 kcal
FAQ
How do I convert British Thermal Unit to Kilocalorie?
Multiply the British Thermal Unit value by 0.2521644007 to get the equivalent value in Kilocalorie.
What is the formula for British Thermal Unit to Kilocalorie?
The formula is kcal = BTU × 0.2521644007.
How many Kilocalorie are in 1 British Thermal Unit?
1 British Thermal Unit equals 0.2521644007 Kilocalorie.
Can I convert Kilocalorie back to British Thermal Unit?
Yes. 1 Kilocalorie equals 3.965666831 British Thermal Unit, and the related converter can reverse the calculation.
What are common names for British Thermal Unit and Kilocalorie?
British Thermal Unit is shown as BTU and may also be searched as btu, british thermal unit. Kilocalorie is shown as kcal and may also be searched as kilocalorie, kilocalories, food calorie.
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