Grams-force to millinewtons converter above calculates how many millinewtons are in 'X' grams-force (where 'X' is the number of grams-force to convert to millinewtons). In order to convert a value from grams-force to millinewtons (from gf to mN) simply type the number of gf to be converted to mN and then click on the 'convert' button.