Unit Converters · Browser · Free

Joules to Calories Converter

Enter an amount in joules, choose which kind of calorie you want the answer in, and press Convert. The result appears in a card below the button.

What this converter does

The form has two parts: a number field for the energy in joules, and a select for the kind of calorie to convert into. The choices are the small thermochemical calorie (cal, 4.184 J), the small 15°C calorie (4.1855 J) and the large food calorie (Cal, 4184 J).

Nothing is worked out until you press Convert. The answer then shows up in a card below the button. Copy writes the result and its unit to the clipboard, and Clear resets the form.

The whole calculation happens in the browser, so the number you entered is not uploaded anywhere.

Joules to calories formula

One thermochemical calorie is exactly 4.184 J by definition, so an amount in joules becomes calories by dividing by 4.184. Written the other way round, 1 J ≈ 0.239005736137667 cal.

The small 15°C calorie is about 4.1855 J, and for it 1 J ≈ 0.238920081232828 cal. The large food calorie, written Cal, is 1 kcal, which is 4184 J; there 1 J ≈ 0.000239005736137667 cal.

Other definitions of the calorie sit close by: one international calorie is exactly 4.1868 J, and the 20°C calorie is about 4.182 J. This page converts to the three kinds named in the select.

Joule to calorie table

The table is worked in the small thermochemical calorie, where 1 J is about 0.239005736 cal. The rest of the rows use that same unit: 10 J ≈ 2.39005736 cal, 100 J ≈ 23.9005736 cal and 1000 J ≈ 239.005736 cal.