- 1 inch = 25.4 millimetres
- 12 inches = 1 foot = 304.8 millimetres
- 36 inches = 1 yard = 914.4 millimetres
- 1 meter = about 39.37 inches
The abbreviation for "inch" is "in" or " (double quote).
In Britain and the United States, people use inches more than they use millimetres or centimetres. Also, road signs for speed limits are in miles per hour other U.S. customary units or Imperial units of measurement are also in common use.
In the rest of the world, metric units are almost always used. The inch is not used by scientists.