How many calories is in 1 gram?

A calorie is a measurement of temperature, whereas a gram is a measurement of weight.

Technically, one calorie is 1/100th the amount of energy it takes to raise 1 gram of air-free water from 0 degrees c (freezing) to 100 degrees c (boiling). This works out to about 4.19 joules.

The number of calories in foods vary by the types of food. One gram of chocolate is going to have many more calories than one gram of wheat.