Mid calf is the most unflattering length on anyone apparently. It certainly is on me.
If the hems hits the biggest part of the calf you will look dumpy. if you are already dumpy you will look wide, very wide.
Above the ankle is a good length. Any longer and if you are like me you will get caught in it and fall over, or if you have boots with fastenings on the outside edge they will catch it in and tie your legs together as you walk. I know this, and my boots have tape on the buckles now.