Calories per day to foot-pound-force per second conversion calculator shown above calculates how many foot-pound-force per second are in 'X' calories per day (where 'X' is the number of calories per day to convert to foot-pound-force per second). In order to convert a value from calories per day to foot-pound-force per second (from cal/d to ft lbf/s) simply type the number of cal/d to be converted to ft lbf/s and then click on the 'convert' button.