British Thermal Unit to Calorie Converter
Energy · unit-converter
Convert British Thermal Unit to Calorie with fixed input and output units, a step-by-step formula line, and reference tables. Factors are joule-based; food energy uses thermochemical calories. The full Energy Converter also includes MMBtu, toe, thermal kWh, and MeV/GeV.
Calculator
From: British Thermal Unit (btu)
To: Calorie (cal)
About British Thermal Unit
The British thermal unit used here is the IT BTU: ≈ 1,055.056 J. It appears in HVAC, heating equipment, and US engineering data.
About Calorie
The small calorie (cal) is 4.184 J in this converter (thermochemical). Do not confuse with the dietary kilocalorie (kcal).
How to convert british thermal units to calories
1 british thermal unit is equal to 252.16440072179731 calorie when both are expressed in joule-equivalents:
1 btu = (1,055.05585262 J ÷ 4.184 J) cal = 252.16440072179731 cal
Each british thermal unit is defined as 1,055.05585262 J and each calorie as 4.184 J in this tool, so one btu equals 1,055.05585262 ÷ 4.184 cal = 252.16440072179731 cal.
Let d(btu) be the numeric amount in British Thermal Unit (btu), and d(cal) the amount in Calorie (cal). Then:
d(cal) = d(btu) × (1,055.05585262 / 4.184)
Equivalently, divide by how many btu fit into one cal (joules per cal divided by joules per btu):
d(cal) = d(btu) ÷ 0.00396566683139
Or: calorie = british thermal unit ÷ 0.00396566683139
Examples
Example #1: Convert 1 btu to calorie
1 btu = 1 btu × (1,055.05585262/4.184) cal = 252.164400722 cal
1 btu = 1 btu ÷ 0.00396566683139 = 252.164400722 cal
Example #2: Convert 10 btu to calorie
10 btu = 10 btu × (1,055.05585262/4.184) cal = 2521.64400722 cal
10 btu = 10 btu ÷ 0.00396566683139 = 2521.64400722 cal
Summary
To convert British Thermal Unit to Calorie, multiply the value in btu by the ratio of joules per btu divided by joules per cal. Equivalently: value_cal = value_btu × (1055.05585262 / 4.184). Numerically, 1 btu equals 252.1644007217973 cal.
Relationship context
You are converting between US / imperial engineering units (BTU, therm, ft·lb) (British Thermal Units) and food / nutrition energy (calories) (Calories). All values are mapped through joules first. The numeric factor is 2.521644e+2.
Conversion tables
| British Thermal Unit (btu) | Calorie (cal) |
|---|---|
| 0.1 | 25.2164400722 |
| 1 | 252.164400722 |
| 2 | 504.328801444 |
| 3 | 756.493202165 |
| 4 | 1,008.65760289 |
| 5 | 1,260.82200361 |
| 6 | 1,512.98640433 |
| 7 | 1,765.15080505 |
| 8 | 2,017.31520577 |
| 9 | 2,269.4796065 |
| British Thermal Unit (btu) | Calorie (cal) |
|---|---|
| 10 | 2,521.64400722 |
| 20 | 5,043.28801444 |
| 30 | 7,564.93202165 |
| 40 | 10,086.5760289 |
| 50 | 12,608.2200361 |
| 60 | 15,129.8640433 |
| 70 | 17,651.5080505 |
| 80 | 20,173.1520577 |
| 90 | 22,694.796065 |
| 100 | 25,216.4400722 |