Energy Converter

Convert joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU and foot-pounds.

About this converter

Electricity bills use kilowatt-hours (1 kWh = 3.6 MJ), food labels use kilocalories (1 kcal = 4,184 J) and heating and cooling use BTU. The “calorie” on a food label is really a kilocalorie.

Common kilocalories (food calories) to kilojoules conversions

To convert kilocalories (food calories) to kilojoules, multiply by 4.184. To go back, divide by the same number (or multiply by 0.239006).

Value	Kilocalories (food Calories) → Kilojoules	Kilojoules → Kilocalories (food Calories)
1	1 kcal = 4.184 kJ	1 kJ = 0.239006 kcal
2	2 kcal = 8.368 kJ	2 kJ = 0.478011 kcal
5	5 kcal = 20.92 kJ	5 kJ = 1.19503 kcal
10	10 kcal = 41.84 kJ	10 kJ = 2.39006 kcal
20	20 kcal = 83.68 kJ	20 kJ = 4.78011 kcal
50	50 kcal = 209.2 kJ	50 kJ = 11.9503 kcal
100	100 kcal = 418.4 kJ	100 kJ = 23.9006 kcal
1,000	1,000 kcal = 4,184 kJ	1,000 kJ = 239.006 kcal

Frequently asked questions

How many kJ in a kcal?

1 kcal = 4.184 kJ.

How many kWh is one “unit” of electricity?

One unit on an Indian or UK electricity bill is 1 kWh.