Both inches and millimeters are units of measurement. Inches belong to the english system of measurement, while millimeters belong to the metric system of measurement.
[header] How to convert inches to millimeters [title] Understand the relationship between inches and millimeters. [step] One inch is internationally accepted as being equivalent to 25.4 millimeters. [substeps] Written as an equation, this relationship is represented as : 1 in = 25.4 mm this official, standardized measurement has been set on international records since 1959.