If you can’t see your knees, your shorts are too long. They should probably end at the distal third of your thigh and the measurement is probably 8 or 9 inches. About 2 years ago, the fashion world dictated mid thigh or tennis shorts as the proper length. I have 2 pairs of plaid Gant shorts left of that size and I’m not sure they have any staying power. Stick with the distal third of the thigh and you’ll be fine.