BTU (th) to Calorie (th) Converter
Convert BTU (th) (BTU) to Calorie (th) (cal) instantly. 1 BTU = 251.995698 cal.
Energy Converter
27 units available
1 BTU = 251.995698 cal
Formula:
cal = BTU × 251.9956978967With your value: 1 BTU = 251.9956979 cal
How big is that?
Everyday references on a logarithmic scale, all expressed in btu (th) so you can sanity-check the result.
Other BTU (th) to Calorie (th) conversions
BTU (th) to Calorie (th) Conversion Table
| BTU (th) (BTU) | Calorie (th) (cal) |
|---|---|
| 0.5 | 125.997849 |
| 1 | 251.995698 |
| 2 | 503.991396 |
| 5 | 1,259.978489 |
| 10 | 2,519.956979 |
| 15 | 3,779.935468 |
| 20 | 5,039.913958 |
| 25 | 6,299.892447 |
| 50 | 12,599.784895 |
| 100 | 25,199.56979 |
| 250 | 62,998.924474 |
| 500 | 125,997.848948 |
| 1000 | 251,995.697897 |
Calorie (th) to BTU (th) Conversion Table
| Calorie (th) (cal) | BTU (th) (BTU) |
|---|---|
| 0.5 | 0.001984 |
| 1 | 0.003968 |
| 2 | 0.007937 |
| 5 | 0.019842 |
| 10 | 0.039683 |
| 15 | 0.059525 |
| 20 | 0.079366 |
| 25 | 0.099208 |
| 50 | 0.198416 |
| 100 | 0.396832 |
| 250 | 0.99208 |
| 500 | 1.984161 |
| 1000 | 3.968322 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
BTU (th) (BTU)
Energy
The International Table BTU is exactly 1055.055 852 62 J.
Thermochemical and 39 °F BTU definitions differ by up to 0.2 %.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Calorie (th) (cal)
Energy
The thermochemical calorie is exactly 4.184 J.
The International Table calorie (4.1868 J) and the 15 °C calorie differ slightly.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
How to Convert BTU (th) to Calorie (th)
To convert from BTU (th) (BTU) to Calorie (th) (cal), multiply the value by 251.9956978967.
Formula: cal = BTU × 251.9956978967
Reverse: BTU = cal × 0.0039683217
Step-by-Step Example
- Start with your value in BTU (th). For example: 5 BTU
- Multiply by the conversion factor: 5 x 251.9956978967
- The result is: 1,259.978489 cal
About BTU (th)
The btu (th) (BTU) is a unit of energy and work. One btu (th) equals 1054.35 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: energy calculations, engineering and science, education.
About Calorie (th)
The thermochemical calorie equals 4.184 joules. Not to be confused with the food Calorie (kcal), which equals 1,000 calories.
Common uses: chemistry, nutrition, heating.
Frequently Asked Questions
How many Calorie (th) are in 1 BTU (th)?
There are exactly 251.9956978967 Calorie (th) in 1 BTU (th). This means the conversion factor from BTU (th) to Calorie (th) is 251.9956978967.
What is the formula to convert BTU (th) to Calorie (th)?
The formula to convert BTU (th) to Calorie (th) is: cal = BTU × 251.9956978967. For example, to convert 10 BTU (th) to Calorie (th), you would multiply 10 by 251.9956978967.
What is a BTU (th)?
The btu (th) (BTU) is a unit of energy and work. One btu (th) equals 1054.35 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What is a Calorie (th)?
The thermochemical calorie equals 4.184 joules. Not to be confused with the food Calorie (kcal), which equals 1,000 calories.
What are the common uses of BTU (th)?
The BTU (th) is commonly used in energy calculations, engineering and science, education.
Related Energy Conversions
Cite this page
UnitConvertLab. (2026). BTU (th) to Calorie (th) converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/btu-to-calorie