▁metric . ▁ ▁A ▁number ▁of ▁other ▁juris dict ions ▁have ▁laws ▁mand ating ▁or ▁perm itting ▁other ▁systems ▁of ▁measurement ▁in ▁some ▁or ▁all ▁context s , ▁such ▁as ▁the ▁United ▁Kingdom ▁– ▁whose ▁road ▁sign age ▁legisl ation , ▁for ▁instance , ▁only ▁allows ▁distance ▁signs ▁displaying ▁imperial ▁units ▁( m iles ▁or ▁yards ) ▁– ▁or ▁Hong ▁Kong . ▁ ▁In ▁the ▁United ▁States , ▁metric ▁units ▁are ▁used ▁almost ▁univers ally ▁in ▁science , ▁widely ▁in ▁the ▁military , ▁and ▁partially ▁in ▁industry , ▁but ▁custom ary ▁units ▁pre dom inate ▁in ▁household ▁use . ▁At ▁ret ail ▁stores , ▁the ▁liter ▁is ▁a ▁commonly ▁used ▁unit ▁for ▁volume , ▁especially ▁on ▁bott les ▁of ▁be ver ages , ▁and ▁mill igr ams , ▁rather ▁than ▁gra ins , ▁are ▁used ▁for ▁medic ations . ▁Some ▁other ▁standard ▁non - SI ▁units ▁are ▁still ▁in ▁international ▁use , ▁such ▁as ▁na ut ical ▁miles ▁and ▁kn ots ▁in ▁av iation ▁and ▁sh ipping . ▁ ▁Met ric ▁system ▁ ▁Met ric ▁systems ▁of ▁units ▁have ▁evol ved ▁since ▁the ▁ad option ▁of ▁the ▁first ▁well - defined ▁system ▁in ▁France ▁in ▁ 1 7 9 5 . ▁During ▁this ▁evolution ▁the ▁use ▁of ▁these ▁systems ▁has ▁spread ▁throughout ▁the ▁world , ▁first ▁to ▁non - English - spe aking ▁countries , ▁and ▁then ▁to ▁English ▁speaking ▁countries . ▁ ▁Multi ples ▁and ▁sub multi ples ▁of ▁metric ▁units ▁are ▁related ▁by ▁powers ▁of ▁ten ▁and ▁their ▁names ▁are ▁formed