Energy converter
Joules, calories, kWh, BTU and therms.
250 kcal is
1,046 kJ
In every unit
- Joules1,046,000 J
- Kilojoules1,046 kJ
- Megajoules1.046 MJ
- Calories250,000 cal
- Watt-hours290.556 Wh
- Kilowatt-hours0.290556 kWh
- British thermal units991.417 BTU
- Therms0.00991417 therm
Show workings
- Conversion factor1 kcal = 4.184 kJ
- Result250 × 4.184 = 1,046 kJ
How it works
Everything converts through joules. A kilowatt-hour (what electricity and gas bills charge for) is 3.6 million joules. A food Calorie is a kilocalorie: 4,184 joules.
Worked example
5 kilowatt-hours is 18 MJ (5 × 3.6).
Kilowatt-hours to megajoules chart
| kWh | MJ |
|---|---|
| 1 | 3.6 MJ |
| 2 | 7.2 MJ |
| 5 | 18 MJ |
| 10 | 36 MJ |
| 50 | 180 MJ |
| 100 | 360 MJ |
| 1,000 | 3,600 MJ |
| 3,000 | 10,800 MJ |
Questions
Are food Calories the same as calories?
No. A food Calorie (capital C, or kcal) is 1,000 small calories. A 250 kcal snack is 1,046 kJ.
How do I convert gas units to kWh?
Gas meters measure volume, so suppliers convert using a calorific value. A therm is 29.31 kWh; for meter readings in cubic metres, your bill shows the factor used.
What is a BTU?
A British thermal unit, about 1,055 joules. Heaters and air conditioners are often rated in BTU per hour.