Heat and energy converter
Convert heat and energy units — joule, calorie, kilocalorie, kilojoule, watt-hour, kilowatt-hour, BTU, foot-pound, erg and electronvolt — with 1 cal = 4.184 J.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
The source to target line first, then every common unit.
Enter an energy value to convert
Units: 0
What this tool does
- Convert nutrition labels and fitness data: 1 kcal = 4.184 kJ and 2000 kcal = 8368 kJ.
- Unify calories, joules and kilowatt-hours for physics and engineering: 1 kWh = 3.6 MJ.
- Translate US energy figures: 1 BTU = 1055.05585262 J.
Example
Input
1
Output
千卡（大卡） (kcal) → 千焦 (kJ)：1 kcal = 4.184 kJ 电子伏 (eV) = 2.6114473967543833e+22 eV 尔格 (erg) = 41840000000 erg 焦耳 (J) = 4184 J 卡 (cal) = 1000 cal 千焦 (kJ) = 4.184 kJ 千卡（大卡） (kcal) = 1 kcal 英热单位 (BTU) = 3.965667 BTU 英尺磅 (ft·lb) = 3085.960033 ft·lb 瓦时 (Wh) = 1.162222 Wh 千瓦时（度） (kWh) = 0.001162 kWh
1 cal = 4.184 J, 1 kcal = 4.184 kJ and 1 kWh = 3.6 MJ are all definition values.
Frequently asked questions
Is a calorie the same as a kilocalorie?
No. 1 kcal = 1000 cal = 4184 J. Nutrition labels almost always mean kcal, but the capital-C “Cal” can also denote kcal — check carefully.
Why is 1 cal = 4.184 J?
That is the thermochemical calorie definition. The International Table calorie is 4.1868 J, about 0.07% larger.
Why does 1 eV show as 0.000000 J?
Because 1 eV = 1.602176634e-19 J, which is 0.000000 when rounded to 6 decimals. Convert the other way for that scale: 1 J = 6.241509074e18 eV.
Why is kWh called a “unit” of electricity?
In Chinese billing it is nicknamed “du”: 1 unit = 1 kWh = 3.6 × 10⁶ J.
Keywords：热量换算energy converter卡路里大卡转千焦焦耳千瓦时BTU卡路里换算