While a millimeter(mm) is a metric unit equal to one thousandth of a meter, an inch(in) is also a unit of length in the imperial and United States customary systems of measurement.
Formula to convert in to mm.
To convert in to mm, we have to know there relationship first.
We are told that 1 inch is equivalent to 25.4 mm.
Therefore, to convert in to mm we multiply the in value by 25.4.
Length in mm = Length in in x 25.4
Convert 20 inches to mm.
= 20 x 25.4
= 508 mm.