To convert btu to calories, multiply by 252.1644007.
The calculation uses 1 BTU = 252.1644007 cal. Results are displayed to at most 10 significant digits. Definitions can be exact while a displayed decimal is rounded. Match the displayed precision to your original measurement.
Uses the International Table BTU. Other BTU definitions differ slightly.
Uses the thermochemical calorie, 4.184 J.
The formula
BTU- Input unit: btu
cal- Output unit: calories
How to use this calculator
- Enter a value in BTU.
- Multiply by the stored conversion factor.
- Read the result in cal; divide by the same factor to convert back.
Worked examples
Worked conversion
1 BTU × 252.1644007 ≈ 252.1644007 cal.
Reverse conversion
252.1644007 cal ÷ 252.1644007 ≈ 1 BTU. Rounding intermediate values can change the last displayed digit.
Frequently asked questions
What factor does this converter use?
It uses 252.1644007 cal per BTU. Uses the International Table BTU. Other BTU definitions differ slightly. Uses the thermochemical calorie, 4.184 J.
Why can another converter show a slightly different answer?
Check the unit convention first (such as US versus Imperial or decimal versus binary), then compare rounding. Measurement uncertainty is separate from the unit conversion.
BTU to cal table
| BTU | cal (rounded) |
|---|---|
| 0 | 0 |
| 1 | 252.1644007 |
| 2 | 504.3288014 |
| 5 | 1260.822004 |
| 10 | 2521.644007 |
| 100 | 25216.44007 |