Joules to Kilocalories Converter
Convert joules to kilocalories — divide by 4,184. Results update as you type; exact factors shown.
One joule is 0.0002 kilocalorie (food Calorie) — see the exact factor, not a rounded rule of thumb.
How the joules to kilocalories converter works
Energy converts through the joule. A thermochemical calorie is exactly 4.184 J, so a food Calorie (kcal) is 4.184 kJ. A kilowatt-hour is exactly 3.6 MJ. A BTU is 1,055.056 J and a US therm is 100,000 BTU.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common energy conversions
| From | To | Units |
|---|---|---|
| 4,184 J | 1 kcal | joules to kilocalorie (food Calorie) |
| 10,000 J | 2.3901 kcal | joules to kilocalorie (food Calorie) |
| 41,840 J | 10 kcal | joules to kilocalorie (food Calorie) |
| 100,000 J | 23.9006 kcal | joules to kilocalorie (food Calorie) |
| 418,400 J | 100 kcal | joules to kilocalorie (food Calorie) |
| 500,000 J | 119.5029 kcal | joules to kilocalorie (food Calorie) |
| 1,000,000 J | 239.0057 kcal | joules to kilocalorie (food Calorie) |
| 2,000,000 J | 478.0115 kcal | joules to kilocalorie (food Calorie) |
| 4,184,000 J | 1,000 kcal | joules to kilocalorie (food Calorie) |
| 8,368,000 J | 2,000 kcal | joules to kilocalorie (food Calorie) |
| 10,000,000 J | 2,390.0574 kcal | joules to kilocalorie (food Calorie) |
| 100,000,000 J | 23,900.5736 kcal | joules to kilocalorie (food Calorie) |
Units in this converter and their exact factors
| Unit | Symbol | One unit in joules |
|---|---|---|
| joule | J | 1 joule |
| kilojoule | kJ | 1,000 joule |
| megajoule | MJ | 1,000,000 joule |
| calorie (thermochemical) | cal | 4.184 joule |
| kilocalorie (food Calorie) | kcal | 4,184 joule |
| watt-hour | Wh | 3,600 joule |
| kilowatt-hour | kWh | 3,600,000 joule |
| British thermal unit | BTU | 1,055.05585262 joule |
| therm (US) | thm | 105,505,585.262 joule |
| foot-pound | ft·lb | 1.3558179483 joule |
FAQFrequently asked questions about energy conversion
How many joules in a kilocalorie?
4,184.
What is 8.368 MJ?
2,000 kilocalories — a common daily intake reference.
What is a food Calorie?
A kilocalorie. The capital C distinguishes it, though almost nobody writes it that way.
What is 1 MJ in kcal?
239 kcal.
Why does nutrition still use calories?
Convention and familiarity. The joule is the correct SI unit and most of the world prints both.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.