Convert calories to joules

Explanation

From this page you can convert calories to joules (or cal to J) simply, by using the application above.

In case you are wondering, to convert from calories to joules you need to multiply by 4.184. This factor is calculated using the respective definitions of the two units you can find below.

Formula

1 cal=4.184 J

caloriescal

dimension	energy
symbol	cal

The calorie (cal) is a unit of energy.

In this converter "calorie" refers to the thermochemical calorie.

When talking about food the word calorie almost always refers to the kilocalorie (kcal).

Definition of the calorie

One calorie is 4.184 joules.

NIST Guide to the SI, Appendix B.9

History

The calorie was first defined as the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius.

The "Thermochemical calorie" was defined by Frederick Rossini simply as 4.1833 international joules in order to avoid the difficulties associated with uncertainties about the heat capacity of water. ^[source]

In 1948 the CGPM abandonned the international ampere for the absolute ampere, ^[source] as a result, the thermochemical calorie was redefined as 4.184 joules exactly to represent the same quantity of energy as before.

Some Facts

Since the tonne of TNT is defined as 4.184 gigajoules, one calorie is the energy equivalent to the detonation of one milligram of TNT (or one nanotonne of TNT).

Calories

calorie	cal	1
kilocalorie	kcal	1000

Related Conversions

joulesJ

dimension	energy
system	International system of units (SI)
symbol	J

The joule (J) is the base unit of energy in the International System of Units.

Definition of the joule

Le joule est le travail produit par un newton dont le point d'application se déplace de un mètre dans la direction de la force.

9^th CGPM (1948) p. 113

That is to say, one joule is the work done by a force of one newton whose point of application moves one meter in the direction of the force.

SI Energy Units

picojoule	pJ	0.000 000 000 001
nanojoule	nJ	0.000 000 001
microjoule	µJ	0.000 001
millijoule	mJ	0.001
joule	J	1
kilojoule	kJ	1000
megajoule	MJ	1 000 000
gigajoule	GJ	1 000 000 000
terajoule	TJ	1 000 000 000 000