Answer to Question #18601 in Molecular Physics | Thermodynamics for brian

Question

how many kilojules are in calories?

Answer 1

A kilojoule is a measuring unit of energy, in the same way that kilometresmeasure distance. Food energy can also be measured in terms of the nutritional
or 'large' Calorie (Cal), which has the same energy value as 4.186 kilojoules
(kJ). This should not be confused with the 'small' or gram calorie, which is
used by scientists to measure the amount of energy required to heat water.
There are 1,000 (small) calories in one (large) Calorie, which is why it is
also sometimes known as a 'kilocalorie'.

4.184 kilojoules = 4,184 joules = 1 Calorie = 1 kilocalorie = 1,000 calories