Calorie to British thermal unit
Calorie (cal)
British thermal unit (BTU)
How it is calculated
Each unit is defined via the base unit (joule (J)). The value is first converted to the base unit, then to the selected unit.
1 cal = 4.184 J
1 BTU = 1055.05585262 J
1 cal × 4.184 = 4.184 J
4.184 J ÷ 1055.05585262 = 0.00396566683139 BTU