Convert feet to millimeters ( ft to mm ) with the length conversion calculator, and learn the foot to millimeter formula. If we want to reverse convert Millimeter to Feet according to the Frequency units reference formula, 1 mm = 0.0032808398950131 ft. You can find automatic conversion rates in the table below. Feet+Inches ( ft +in) to millimeters ( mm ) conversion calculator and how to convert. Instant free online tool for foot to millimeter conversion or vice versa. The foot [ ft ] to millimeter [ mm ] conversion table and conversion steps are also listed. Also, explore tools to convert foot or millimeter to other length units or learn more about length conversions.