Twin XL Mattress vs. Full/Double Mattress

There are several factors to consider when deciding on the best mattress size, including bedroom size, shopping budget, and the number of people who plan to sleep on the bed. Most mattresses sold today are available in six standard sizes: Twin, Twin Extra Long (XL), Full/Double, Queen, King, and California King. Additionally, select brands and models offer specialty and custom sizes.

This guide will compare the Twin XL and Full/Double sizes. To start, let’s look at the basic differences between these two sizes.

Key Differences and Similarities between Twin XL and Full/Double Sizes

Size Twin Extra Long (XL) Full/Double
Standard Width 38″ (3 1/6′) 54″ (4 1/2′)
Standard Length 80″ (6 2/3′) 75″ (6 1/4′)
Ideal Bedroom Size Minimum: 7 1/6′ x 10 2/3′ Minimum: 8 1/2′ x 10 1/4′
Average Price $500 to $750 $550 to $800
Ideal Sleeping Arrangement Single sleepers who are too tall for a standard Full/Double, but do not require extra sleeping space in terms of mattress width. Single sleeper who is average height and prefers some extra sleeping space.

Pros and Cons of a Twin XL Size

A Twin Extra Long, or Twin XL, measures eighty inches (80″) long, which is five inches (5″) longer than a standard Twin and Full/Double; both a Twin and Twin XL measure roughly thirty-eight inches (38″) wide. The Twin XL is equivalent to one-half of a standard King-size mattress (76W” x 80L”), and is ideal for sleepers who are too tall for a standard Twin-size mattress. However, the Twin XL is usually too narrow to accommodate more than one person.

Benefits of a Twin XL mattress include the following:

  • Less space required: Although a Twin XL is five inches longer than a Full/Double, they take up less overall space. A Twin XL measures a total of 3,120 square inches, while a Full/Double measures 4,050 square inches. This makes the Twin XL more suitable for narrower bedrooms.
  • Lower price-point: A Twin XL mattress is normally priced $50 to $300 lower than a Full/Double version of the same model. In rare cases, the Twin XL and Full/Double sizes will share the same price-point.
  • Long enough for most sleepers: A Twin XL will accommodate anyone who stands at 6’7″ or shorter; in contrast, the Full/Double will be too short for anyone who stands 6’3″ or taller.

Some drawbacks of a Twin XL mattress include the following:

  • Less width for single sleepers: A Twin XL mattress is roughly sixteen inches (16″) narrower than a Full, and is not ideal for single sleepers that prefer extra space.
  • Not couple-friendly: A Twin XL measures roughly thirty-eight inches (38″) wide, making it too cramped for most couples.
  • Limited availability: Although Twin XL sizes are fairly common, this size is not as widely available as the Full/Double size.

Pros and Cons of a Full/Double Size

full double mattress sizeAlso known as a Double, the Full-size mattress measures fifty-four inches (54″) wide by seventy-five inches (75″) long. The Full/Double is ideal for individual sleepers who require a wider sleeping space. For this reason, Full/Double beds are often used in hotels and motels, college dorms, healthcare facilities, and other commercial establishments. Like the Twin XL, Full/Doubles are typically not suitable for couples.

Benefits of a Full/Double mattress include the following:

  • Extra space: A Full/Double mattress is five inches (5″) shorter than a standard Twin XL, but the size is roughly sixteen inches (16″) wider. For this reason, a Full/Double is suitable for single sleepers who feel too cramped on Twin XL sizes.
  • Wide availability: Most mattresses sold today are available in a Full/Double size, including models that are not offered in a Twin XL.  

Drawbacks of Full/Double mattresses include the following:

  • Higher price-point: The average Full/Double mattress costs $50 to $300 more than a Twin XL version of the same model, though some brands assign the same price-point to Full/Double and Twin XL mattresses.
  • Not long enough for exceptionally tall people: While a Twin XL is suitable for anyone who stands under 6’8″, a Full/Double is too short for anyone who stands at 6’3″ or taller.
  • Not couple-friendly: Like the Twin XL, a Double/Full will be too narrow for most couples to sleep comfortably, and should be considered suitable for single sleepers only.

Is a Twin XL or Full/Double Size Right for You?

When comparing the Twin XL and Full/Double sizes, here are a few important questions to keep in mind:

  • How tall is the individual who plans to use the mattress?
  • Does the owner prefer to have an extra-wide sleep surface, or will a narrower surface be adequate?
  • What is the shopper’s mattress budget?
  • What is the size and shape of the bedroom where the purchaser plans to use the mattress?


The choice between Twin XL and Full/Double mattresses is essentially a trade-off. The Twin XL is a slightly longer option that is suitable for anyone who stands at 6’7″ or shorer, while the Full/Double offers a more expansive sleep surface that is sixteen inches (16″) wider. Prices are usually negotiable between the two sizes, and neither one will usually cost more than $800. Neither the Twin XL nor the Full/Double are intended for use by more than one sleeper, though — in a pinch — both can accommodate two sleepers with very limited sleeping space.

It’s important to note that these findings are largely subjective. If you are unsure which size will work best for you, we recommend testing both the Twin XL and Full/Double sizes in brick-and-mortar mattress stores. In addition, mattress sleep trials allow you to sleep on both sizes in the comfort of your own home for prolonged periods of time. Simply return the size you are least satisfied with before that sleep trial ends.

For more information on mattress size comparisons, please visit the following Tuck pages: