How to convert Calorie to British thermal unit

Conversion factor and calculation steps from Calorie (cal) to British thermal unit (BTU).

Conversion logic

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