Inches per minute to millimeters per second conversion calculator above calculates how many millimeters per second are in 'X' inches per minute (where 'X' is the number of inches per minute to convert to millimeters per second). In order to convert a value from inches per minute to millimeters per second (from in/min to mm/s) just type the number of in/min to be converted to mm/s and then click on the 'convert' button.