||The English used in this article may not be easy for everybody to understand. (June 2012)|
A shirt is a kind of cloth which is made to cover the chest and upper body. In North America this covers many types of clothes, including T-shirts and, polo shirts etc. In British English, a shirt has a garment with a collar, sleeves with cuffs and a full vertical opening with buttons. (North Americans would call that a "dress shirt", a specific type of "collared shirt".). Some shirts have sleeves, which cover the arms. T-shirts are a type of shirt which has smaller sleeves. These sleeves cover the shoulders. Shirts which do not have sleeves are sleeveless.
The basic measure are from XXXL (very large) (XXL XL L M S) to XXS used for industrial productions. More accurate measure use the collar has indication from 37 cm (14 inc.)up to 50 cm. Only shirts made by tailors (people who make clothes as a living) take many measurements into account  for a more fitting shirt.