Calories (15 °C) to joules converter on this page calculates how many joules are in 'X' calories (15 °C) (where 'X' is the number of calories (15 °C) to convert to joules). In order to convert a value from calories (15 °C) to joules (from cal to J) simply type the number of cal to be converted to J and then click on the 'convert' button.