Work out joule to calorie instantly with clear inputs, formula shown and shareable results.
Converting Joules to Calories is one multiplication: a single J is 0.23900574 cal, so the amount is scaled by that factor. Reversing the direction divides by the same factor. The factor is an exact definition rather than a rounded figure, so the result stays precise at any magnitude. This uses the thermochemical calorie of exactly 4.184 J. A food 'Calorie' on a nutrition label is a kilocalorie — 1,000 of these.
Joules → Calories
cal = J × 0.23900574
Calories → Joules
J = cal ÷ 0.23900574
One J equals 0.23900574 cal. That value is exact by definition.
Divide by 0.23900574 rather than multiplying, or flip the direction selector which does it for you.