Convert an energy amount between physics, food and electricity units.
Try an example
Load a ready-made sample into this tool and run it. Every result you see is calculated live by the tool itself — nothing here is a pre-written answer.
Sample: value: 100; from: kcal; to: kJ
How to Use
- Enter an energy value.
- Choose the current unit and the target unit.
- Read the converted energy.
What this energy converter does
This energy converter converts energy amounts between joules, kilojoules, calories, kilocalories, watt-hours, and kilowatt-hours. Enter a value, choose its current unit and the unit you need, and read the converted result. Those units span three worlds that rarely meet on a single page: physics and engineering, food and nutrition, and household electricity, which is exactly why one shared converter is useful.
The relationships behind the conversion
One kilocalorie is 4,184 joules, and one kilowatt-hour is 3.6 million joules, the same energy as running a 1,000-watt appliance for an hour. Food energy is quoted in kilocalories, electricity bills in kilowatt-hours, and scientific work in joules, so converting between them lets you compare a meal, a battery, and a homework problem on one scale.
Good to know
The calories on food labels are kilocalories, and this converter follows that convention: 1 kcal equals 4,184 joules exactly. Small calories are also offered for scientific contexts. Results are rounded to six decimal places, and no other energy units are included.
Frequently asked questions
Are food calories the same as the calories here?
Food labels use kilocalories, written as kcal here and sometimes as Calories with a capital C. This converter's kilocalorie is that unit: 1 kcal equals 4,184 joules of energy.
How do I convert kilowatt-hours to joules?
Enter the value and convert from kilowatt-hours to joules. One kilowatt-hour equals 3.6 million joules, so even small electricity amounts become large joule figures, which the tool handles directly.
Can I convert joules to kilocalories for a recipe?
Yes. Choose joules as the starting unit and kilocalories as the target. That direction is common when a physics or engineering figure needs to be compared with nutrition information.
How to use Energy Converter
- Enter an energy value.
- Choose the current unit and the target unit.
- Read the converted energy.
Limitations
Food calories here are kilocalories (1 kcal = 4184 J); results round to 6 decimal places.