Esquire Manual: How To Wear Shorts
The basic rules of showing leg.
There is no single prescribed length for shorts, but there is a clear sweet spot: an inch (or about 3cm) above your kneecap. Consider it a starting point, and add or subtract from there based on your comfort level with your body.
If you are of thick leg or small stature, shorts that hit higher on the thigh will stretch you out a bit. And in order to avoid confusing bulges, the shorter your shorts, the fewer things you’ll want to carry in your pockets.
If you are tall or have thin legs, the opposite is true—your shorts should fall closer to your knee. The longer they are, the more fitted they should be. You should also consider a cuff, which will give the illusion of heft. And unless you’re actively harvesting clams, it’s never okay to go past the knee.