Calories per second to kilocalories per second converter above calculates how many kilocalories per second are in 'X' calories per second (where 'X' is the number of calories per second to convert to kilocalories per second). In order to convert a value from calories per second to kilocalories per second (from cal/s to kcal/s) simply type the number of cal/s to be converted to kcal/s and then click on the 'convert' button.