British Thermal Units to Kilocalories Converter
1 British thermal unit ≈ 0.252164401 kilocalories
Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
This is the unit written as "Calories" on nutrition labels.
1 British thermal unit equals 0.252164 kilocalories
How to convert British thermal units to kilocalories
Calories here are thermochemical (4.184 J), while BTU uses the International Table definition. A kilowatt-hour is energy (3.6 MJ), not power; a food Calorie is a kilocalorie.
kcal = BTU × 0.2521644007One British thermal unit is 0.2521644007 kilocalories, so a single multiplication converts any value.
2.52164 kcal ≈ 10 × 0.2521644007Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
This is the unit written as "Calories" on nutrition labels.
British thermal units to kilocalories conversion table
Common values in British thermal units, converted to kilocalories.
| British thermal units (BTU) | Kilocalories (kcal) |
|---|---|
| 1 | 0.2521644 |
| 2 | 0.5043288 |
| 3 | 0.7564932 |
| 4 | 1.0086576 |
| 5 | 1.260822 |
| 10 | 2.521644 |
| 20 | 5.043288 |
| 25 | 6.30411 |
| 50 | 12.60822 |
| 100 | 25.21644 |
| 250 | 63.0411 |
| 500 | 126.0822 |
| 1,000 | 252.1644 |
About these units
British thermal unitBTU
The International Table BTU: 1,055.05585262 joules. The US heating and cooling unit.
Reference: NIST Special Publication 811.
kilocaloriekcal
One thousand thermochemical calories: exactly 4,184 joules.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.