LAPEL WIDTH For Overcoats, the lapels are pretty standard width, so this is a non-issue. The lapels on the Brooks Brothers Overcoat above are a little wide, but they’re still very acceptable. HOW LONG SHOULD AN OVERCOAT BE? No matter what climate you live in, it should end somewhere above your knee – never longer. A good rule of thumb is mid-thigh to just above your knee is where your Overcoat should hit.