Length of sleeves in short-sleeve shirts

[Bede735]

What is the right length of sleeve in a short-sleeve shirt? Some of my shirts extend right down to the elbow, but I feel that's too long (and modest). Yet if it is too short that may appear feminine, as sleeves on women's t-shirts seem to be designed shorter.

[Torchwatch]

Am wearing a French tee shirt as I write this and am therefore stylish, the "correct arm length is between a third and a half way between the shoulder and the elbow. This allows the biceps to be partially yet casually displayed.

There was a fashion for tee shirts with mini sleeves but they seem not to be around any more and were worn by bad boys.

Ebay is selling sleeveless tee shirts:
https://www.ebay.co.uk/itm/Fruit-of-...m7h1 wIGhG5ag

Not exactly a vest as a vest has a cut away shoulder, not seen anyone wearing them.