Kilocalories to Joules converter

Convert kilocalories (kcal) to joules (J) — results update instantly as you type.

Kilocalories to Joules

To4,184

1 kcal = 4,184 J

How to convert Kilocalories to Joules

Energy appears as joules in physics, calories in nutrition, and kilowatt hours on electricity bills. All measure the same thing — the capacity to do work — just at very different scales.

Everything converts through the joule. One (small) calorie is exactly 4.184 joules, a food Calorie (kcal) is 4,184 joules, and one kilowatt hour is exactly 3.6 million joules.

Formula

kcal × 4,184 = J

Multiply your kilocalories value by 4,184 to get joules. For the reverse, divide by the same factor.

Kilocalories to Joules conversion table

KilocaloriesJoules
1 kcal4,184 J
2 kcal8,368 J
5 kcal20,920 J
10 kcal41,840 J
25 kcal104,600 J
100 kcal418,400 J

Common use cases

  • Comparing food energy (kcal) with exercise burn
  • Understanding electricity bills in kWh
  • Physics and engineering calculations in joules
  • Battery capacity comparisons in watt hours

Frequently asked questions

A food Calorie (capital C) is actually a kilocalorie — 1,000 small calories. Nutrition labels always mean kilocalories.