The millimeter equals one thousandth of a meter and is essential in precision engineering, manufacturing and rainfall measurement. A 10-millimetre rainfall is a moderate shower; over 50 mm in a day is classified as heavy. Machined parts, screws and PCB dimensions are all given in mm.
Real-world: A 2 euro coin is 25.75 mm across and 2.2 mm thick. Rainfall of 50 mm in 24 h is a red-warning event in most of Europe.
Read full millimeter reference โThe yard equals 0.9144 meters exactly, or 3 feet. It is the standard field unit in American football (100-yard field) and British cricket (22-yard pitch). Fabric and textile in Anglo-Saxon countries is still sold by the yard. Historically the yard was said to be the length of King Henry I of England's arm.
Real-world: An NFL football field is 100 yards = 91.44 metres. A cricket pitch is 22 yards = 20.12 metres.
Read full yard reference โ