Energy converter

Joules to Calories Converter

Convert joules into small calories and food Calories (kcal), plus kilojoules and watt-hours.

How Joules to Calories works

The calorie and the joule both measure energy. One thermochemical calorie equals 4.184 joules, so to convert joules to calories you divide by 4.184.

The food Calorie shown on nutrition labels is actually a kilocalorie (kcal) — 1,000 small calories, or 4,184 joules. This converter shows both so you can move between physics and nutrition units.

Formula

1cal = J ÷ 4.184

2kcal = J ÷ 4184

1 cal = 4.184 J · 1 kcal (food Calorie) = 4,184 J = 4.184 kJ

Joules to Calories conversion table

Reference Table6 rows

Common joule values converted to calories and food Calories.
Joules↕	Calories (cal)↕	Food Calories (kcal)↕
100 J	23.9 cal	0.0239 kcal
1,000 J	239 cal	0.239 kcal
4,184 J	1,000 cal	1 kcal
10,000 J	2,390 cal	2.39 kcal
100,000 J	23,901 cal	23.9 kcal
1,000,000 J	239,006 cal	239 kcal

💡 Click any row to auto-fill the calculator aboveClick column headers to sort

FAQ: Joules to Calories

How do you convert joules to calories?

Divide the energy in joules by 4.184 to get small calories, or by 4,184 to get food Calories (kcal). For example, 2,000 J ÷ 4.184 ≈ 478 cal ≈ 0.478 kcal.

Is a food Calorie the same as a calorie?

No. A food Calorie (capital C) is a kilocalorie — 1,000 small calories. So 1 food Calorie = 4,184 joules, while 1 small calorie = 4.184 joules.

How many joules are in a kilocalorie?

One kilocalorie (one food Calorie) equals 4,184 joules, or 4.184 kilojoules.

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