Joules to Kilocalories converter

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

Joules to Kilocalories

To0.000239

1 J = 0.00023901 kcal

How to convert Joules to Kilocalories

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

J × 0.0002390057 = kcal

Multiply your joules value by 0.0002390057 to get kilocalories. For the reverse, divide by the same factor.

Joules to Kilocalories conversion table

JoulesKilocalories
1 J0.000239 kcal
2 J0.000478 kcal
5 J0.001195 kcal
10 J0.00239 kcal
25 J0.005975 kcal
100 J0.023901 kcal

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.