Kilojoules to Calories Converter

A food calorie is exactly 4.184 kilojoules:

calories (kcal) = kilojoules ÷ 4.184

The word "calorie" is doing two jobs. The one on a nutrition label is a kilocalorie — 1,000 of the calories a physicist means. A label saying "250 calories" means 250 kcal, or 250,000 small calories. Every figure on this page uses the food calorie, which is what "kcal" and "Cal" both denote.

Which unit a label leads with depends on the country. Australia, New Zealand and much of Europe print kilojoules first; the US, UK and Canada lead with calories. EU labels are required to show both.

Daily intakes, converted:

• 8,700 kJ → 2,079 kcal — the Australian reference daily intake
• 8,400 kJ → 2,008 kcal — the EU reference for an average adult
• 10,000 kJ → 2,390 kcal
• 2,000 kcal → 8,368 kJ — the US reference value

Everyday foods:

• A banana, 450 kJ → 108 kcal
• A slice of bread, 350 kJ → 84 kcal
• A can of cola, 590 kJ → 141 kcal
• A Big Mac, 2,180 kJ → 521 kcal

For a quick mental figure, divide kilojoules by 4 and take off 5% — or just divide by 4 and accept a 4.6% overestimate, which is smaller than the error in most portion estimates anyway.

Food energy labels are themselves approximate: US regulations permit up to 20% variance from the stated value.