1 in = 25.400 mm 2 = 50.800 3 = 76.200 4 = 101.600 5 = 127.000 6 = 152.400 7 = 177.800 8 = 203.200 9 = 228.600 10 = 254.000
In 1958 the United States and countries of the Commonwealth of Nations defined the length of the international inch (in) is to be exactly 25.4 millimeters (mm). This Online Conversion Calculator converts in both directions.