In the nineteenth century, normal shirt sizes were 14.5 to 17 and today, more than a century later, these sizes are still considered to be the norm in exactly the same way: by next and sleeve. Nowadays there have been some extra mens sizes now available with the addition of 17.5, 18, 18.5 and 19… the king-sized shirt if the day.
Work shirts, knit shirts and sports shirts have evolved on their own, or mirrored dress shirts in their style features. Mens shirts had always been long sleeved or protection, until a detachable sleeve appeared during WW1, along with an actual short sleeve version.
Usually, if you wanted shorter sleeves when working in the hot summer months (in the UK???) you just rolled up those long sleeves. For the first three decades of the twentieth century, casual attire for golf, tennis, table tennis or other sports was a soft negligee shirt without a necktie and rolled up sleeves.
The early years of WWII changed some buttonholes from vertical to horizontal orientation… brought about by the popularity of the Hawaiian shirt. Casual shirts still sported fastenings up to the neck so they could be work with a necktie, or worn with the neck widely opened.
After wearing starched uniforms and still wool military clothing for years, men returning from the war wanted casual shirts that were soft all over and with no starch. They wanted the more casual look for their leisure time after work. They also wanted unique shirts after the previous years on always wearing a uniform and Hawaii print patterns, fancy western shirts, bold colours…. even pink and topstitching as a style detail.
In the late 1940s casual knits were sized as S, M, L or XL and dress shirts were sized by neck and sleeve length so a 15 x 33. As the 1950 started it was clear that fashion would follow the decade that was colourful and would be become influenced by movie stars, celebrities and Rock ‘n’ Roll giants.