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