Common Imperial units and U.S. customary units of length include: inch (25.4&nbsp;mm) mil (one thousandth of an inch, one thou ) foot (12&nbsp;inches, 0.3048 m) yard (3&nbsp;ft, 0.9144 m) (terrestrial) mile (5280&nbsp;ft, 1609.344 m) Marine In addition, the following are used by mariners: fathom (for depth; only in non-metric countries) (2