Twin XL Mattress Dimensions & Measurements: Width & Length

Twin XL Mattress Dimensions Are 39″ X 78″

The Twin XL Mattress Dimensions are very similar to the normal Twin Mattress. The Twin XL has an added 5 inches in length. This makes it a great size for growing children. Instead of buying the next size up (Double), you can get the Twin XL. Due to its extended length, it costs more than the Twin, but can be a very wise investment if you are only looking for a new mattress based off the users growth. It is very similar to the Twin mattress. Therefore, its audience is almost one in the same. Often times this bed is used for teenagers and adults saving on room space. This is also a cheaper way to get a mattress that fits your needs. There are several pros and cons associated with selecting a mattress with Twin XL Mattress dimensions. Listed below are just a few.


  • The cost of a Twin XL is lower than a Double, Queen, King, Or California King.
  • This mattress size can be perfect for those who outgrow a Twin, but do not have the room space for a Queen size mattress.
  • If two growing children are sharing a room, two Twin XL mattresses will take up less space than upgrading to two Double mattresses.
  • The Twin XL can be found in many different qualities and price points.
  • Bunk beds can be found to fit the Twin XL mattress dimensions.


  • Most people will not have this size through their entire adult life so an upgrade to a larger size will eventually be made. Because mattresses can last for so long, it may be more economical to skip this size and invest in a larger size to begin with. However, it is a good replacement for the Twin.
  • This size mattress only fits one full size adult in most cases.

Rest Right Mattress carries a number of different brands to name a few Nature’s Sleep, Glideaway, and iAdjust to help with your sleep.