Size

• A standard twin mattress is 39 inches wide and 75 inches long. A twin XL mattress is also 39 inches wide but is 80 inches long. For comparison, the 75-inch length of the standard twin is the same length as a full-size mattress. The 80-inch length of the twin XL is equal to the length of a king-size mattress.
  
  

Benefits

• Either size of twin mattress can be a good match for a single sleeper, particularly in a smaller bedroom. However, many people taller than about 5'5" find a 75 inch mattress too short for comfort. The twin XL allows a taller sleeper room to stretch out while sleeping. This is why many college dormitories feature twin XL beds--many college-age students need the extra length to get a good night's sleep.
  
  

Considerations

• Twin XL mattresses are less common than twin, so it's sometimes difficult to find the right size bedding to fit them. Online specialty stores sell twin XL bedding. Another option is to shop for the bedding around back-to-school time in August, since more stores carry twin XL bedding when students are buying bedding for dorm rooms. It can be difficult to find twin XL bedding in mature styles, since college campuses are the most common place to find the beds.
  
  

Cost

• Mattress prices vary widely based on the brand and quality of the mattress, but in any brand or style, a twin mattress is the least expensive option. A twin XL mattress costs slightly more than a standard twin, but it's still cheaper than a full, queen or king mattress. The real cost difference between a twin and twin XL mattress may become apparent over time, as the difficulty finding twin XL bedding limits the ability to buy bedding on sale or at discount stores.
  
  

Other Options

• Two twin XL mattresses side by side make a bed surface the same size as a king mattress. Because twin mattresses are so much easier to move than a king, many people opt to buy two twin XL mattresses and cover them with king-size bedding rather than buying a king bed. This is an especially a good option for people who expect to move frequently or who have to maneuver a mattress up a staircase to put it in place. This method also allows for rotating the mattresses, eliminating the problem of bed edges sagging more than the middle.