Joules to calories conversion

Small & large calories

Small calorie (cal) is the energy needed to increase 1 gram of water by 1°C at a pressure of 1 atmosphere.

Large calorie (Cal) is the energy needed to increase 1 kg of water by 1°C at a pressure of 1 atmosphere.

Large calorie is also called food calorie and is used as a unit of food energy.

How to convert from joules to calories

Joules to thermochemical calories

1 cal_th = 4.184 J

The energy in thermochemical calories E_(calth) is equal to the energy in joulesE_(J) divided by 4.184:

E_(cal) = E_(J) / 4.184

Joules to 15°C calories

1 cal₁₅ = 4.1855 J

The energy in 15°C calories E_(cal15)is equal to the energy in joules E_(J) divided by 4.1855:

E_(cal15) =E_(J) / 4.1855

Calories to joules conversion