| − | A sub-unit of linear measurement of the [[Meter| meter]]. Millimeter is equal to one thousandth of a meter. 25.4 millimeters equal one [[Inch| inch]]. | + | A '''Millimeter''' (mm) is a [[Metric system|metric]] unit of measurment equal to one thousandth of a [[Meter| meter]]. An [[Inch|inch]] is equal to 25.4 mm. |