1 kcal = 4184 J
1 kilocalorie equals 4184 joules. To convert kilocalories to joules, multiply the kilocalorie value by 4184. For quick reference: 1 kcal = 4184 J, 5 kcal = 20920 J, 10 kcal = 41840 J, 100 kcal = 418400 J.
Joules = Kilocalories × 4184Start with your value in kilocalories.
Multiply the kilocalorie value by 4184. This is the exact conversion factor from kilocalories to joules.
The product is your value in joules. For example, 5 kcal × 4184 = 20920 J.
The exact factor from kilocalories to joules is 4184.
Joules = Kilocalories × 4184
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 0.001 kcal | 4.184 J |
| 0.01 kcal | 41.84 J |
| 0.1 kcal | 418.4 J |
| 0.5 kcal | 2092 J |
| 1 kcal | 4184 J |
| 1.5 kcal | 6276 J |
| 2 kcal | 8368 J |
| 5 kcal | 20920 J |
| 10 kcal | 41840 J |
| 20 kcal | 83680 J |
| 50 kcal | 209200 J |
| 100 kcal | 418400 J |
| 200 kcal | 836800 J |
| 250 kcal | 1046000 J |
| 500 kcal | 2092000 J |
| 1000 kcal | 4184000 J |
| 2000 kcal | 8368000 J |
| 2500 kcal | 10460000 J |
| 3600 kcal | 15062400 J |
| 5000 kcal | 20920000 J |
| 7500 kcal | 31380000 J |
| 10000 kcal | 41840000 J |
| 25000 kcal | 104600000 J |
| 50000 kcal | 209200000 J |
| 100000 kcal | 418400000 J |
| 250000 kcal | 1046000000 J |
| 500000 kcal | 2092000000 J |
| 1000000 kcal | 4184000000 J |
| 2000000 kcal | 8368000000 J |
| 3600000 kcal | 15062400000 J |
| 5000000 kcal | 20920000000 J |
| 10000000 kcal | 41840000000 J |
| 25000000 kcal | 104600000000 J |
| 50000000 kcal | 209200000000 J |
| 100000000 kcal | 418400000000 J |
| 250000000 kcal | 1046000000000 J |
| 500000000 kcal | 2092000000000 J |
| 1000000000 kcal | 4184000000000 J |
| 2000000000 kcal | 8368000000000 J |
| 5000000000 kcal | 20920000000000 J |
| 10000000000 kcal | 41840000000000 J |
| 20000000000 kcal | 83680000000000 J |
| 50000000000 kcal | 209200000000000 J |
| 100000000000 kcal | 418400000000000 J |
| 1000000000000 kcal | 4.1840 × 10^15 J |
| 10000000000000 kcal | 4.1840 × 10^16 J |
| 100000000000000 kcal | 4.1840 × 10^17 J |
| 1000000000000000 kcal | 4.1840 × 10^18 J |
| 10000000000000000 kcal | 4.1840 × 10^19 J |
| 100000000000000000 kcal | 4.1840 × 10^20 J |
A medium apple has about 95 kcal. An adult's daily energy need is roughly 2,000–2,500 kcal. In joules, that gives you: 1 kcal = 4184 J, 10 kcal = 41840 J, 100 kcal = 418400 J.
The kilocalorie (kcal) equals exactly 4,184 joules — 1,000 small calories. This is the 'Calorie' (capital C) printed on US nutrition labels: when a food package says '250 Calories', it means 250 kcal. Outside the US, food energy is usually labeled in kJ as well.
The joule (J) is the SI derived unit of energy, work, and heat — defined as the energy transferred when a force of one newton acts over one meter. The joule is the standard unit in physics, chemistry, and most modern engineering documentation.