Kilocalories to Calories Converter
Convert kilocalories to small calories — multiply by a thousand. Results update as you type; exact factors shown.
One kilocalorie (food Calorie) is 1,000 calorie (thermochemical) — see the exact factor, not a rounded rule of thumb.
How the kilocalories to calories 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 US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common energy conversions
| From | To | Units |
|---|---|---|
| 1 kcal | 1,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 10 kcal | 10,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 50 kcal | 50,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 100 kcal | 100,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 250 kcal | 250,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 500 kcal | 500,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 1,000 kcal | 1,000,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 1,500 kcal | 1,500,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 2,000 kcal | 2,000,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 2,500 kcal | 2,500,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 3,000 kcal | 3,000,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
| 5,000 kcal | 5,000,000 cal | kilocalorie (food Calorie) to calorie (thermochemical) |
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 calories in a kilocalorie?
1,000.
Is a food Calorie a kilocalorie?
Yes. The capital C distinguishes it, though almost nobody writes it that way.
What is 2,000 kcal in small calories?
Two million.
Why does the distinction matter?
Only in chemistry, where the small calorie is still occasionally used. In nutrition, "calorie" always means kilocalorie.
What is 500 kcal in kJ?
2,092 kJ.
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 Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.