A Twin XL bed measures 38 inches wide and 80 inches long. This makes it 5 inches longer than a standard Twin bed, which is 75 inches long. The extra length of the Twin XL bed makes it a good choice for taller individuals, such as adults over 6 feet tall or growing teens, while maintaining the same narrow width suited for single sleepers. Twin XL beds are also popular in college dorms and smaller living spaces like studio apartments because they provide more length without taking up much more floor space than a regular Twin bed.