Energy Converter (kWh, J, kcal, BTU)
By Santaji GadepatilinUpdated October 27, 2026
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Type in any field to change it. Press × on a value to calculate that field instead.
How to use this converter
Type an energy value in any unit and the others update instantly — useful for electricity bills, food labels, heating and engineering.
Formula
1 kWh = 3.6 MJ = 3,412 BTU 1 kcal = 4.184 kJ 1 therm = 100,000 BTU
Example: 1 kWh = 3,600 kJ = 860 kcal = 3,412 BTU. A 2,000 kcal daily diet is about 2.3 kWh of energy.
Conversion table
| kWh | MJ |
|---|---|
| 0.1 kWh | 0.36 MJ |
| 1 kWh | 3.6 MJ |
| 10 kWh | 36 MJ |
| 100 kWh | 360 MJ |
| 1,000 kWh | 3,600 MJ |
| kcal (food Calories) | kJ |
|---|---|
| 1 kcal | 4.184 kJ |
| 100 kcal | 418.4 kJ |
| 250 kcal | 1,046 kJ |
| 500 kcal | 2,092 kJ |
| 2,000 kcal | 8,368 kJ |
Food calories
On food labels, “Calories” with a capital C are kilocalories (kcal). Many countries also print kJ: 1 kcal = 4.184 kJ.
Energy vs power
Energy (kWh, J) is an amount. Power (kW, W) is the rate of using it. A 2 kW heater running for 3 hours uses 2 × 3 = 6 kWh. Use the power converter for kW, hp and BTU/h.
Frequently asked questions
How many joules are in 1 kWh?
3.6 million joules (3.6 MJ).
How many kJ are in a kcal?
4.184 kJ.
How many BTU are in a kWh?
About 3,412 BTU.