In shoe sizes, 4E represents the extra-wide width for mens shoes. It is a typical width letter used to signify something being extra-wide in mens shoe sizing charts. 2E and 4E are the most frequent E letters in this range, and the more Es added, the bigger the overall width. For womens shoes, the letter size B is considered a medium/normal/standard size, while for men, its a D width. Different manufacturers may use different width sizing conventions, so its essential to check the sizing chart for each manufacturer.