A short sleeve covers the shoulder and ends on the upper arm, somewhere between the armpit fold and the elbow. Tees, polos, camp-collar shirts and summer dresses all live in this band, and within it small differences carry register. A cap sleeve, cut so short it only covers the shoulder cap, reads dressy. Longer, looser short sleeves read athletic.
The hem's landing point on the bicep decides how the arm reads. Cloth stopping at the widest point of the muscle draws a line exactly where the arm is thickest, which visually widens it. Hems ending a little above or below sit cleaner. A snugger opening reads sharper than a flapping one. Sleeve width matters as much as length here, since a wide tube adds bulk the way a wide trouser leg does. Rolling a too-long short sleeve once usually lands it better, and the rolled hem adds visual weight a thin arm can use.
The formality limit is the main trade-off. Short sleeves top out at business casual. Tailoring convention keeps jackets over long sleeves. A short-sleeved shirt under a blazer leaves a bare forearm inside the jacket sleeve, which is why the combination reads off. In pure summer terms nothing beats the length for sun-and-air balance: the shoulder is protected, the forearm is cooled, and laundering is as easy as clothing gets.
In photos
Short Sleeve on real products
See this option on different products. Open a photo for a larger view, or select the name to read its guide.