A full-sized mattress, also known as a "double," is 53 inches wide, 15 inches wider than a twin-size mattress. While it's not a roomy mattress size for a couple, it does offer conveniences that a queen can't. For small bedrooms, it's a space saver. Additionally, full-sized sheets are generally cheaper than queen-sized sheets. Finally, as a youth bed, it can accommodate the sleeping needs of a growing child.

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For adults taller than 5-foot-5-inches, a full-sized mattress can be uncomfortably small.

Number of Sleepers

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Before purchasing a full-sized mattress, assess your own sleeping style and comfort needs.

According to Rocky Mountain Mattress, a full-sized mattress, 53 inches wide by 75 inches long, leaves only 27 inches of extra room for couples who choose it over a queen-sized mattress. While the cost of a full-sized mattress, generally cheaper than a queen, might seem appealing, it may not be roomy enough for two sleeping adults.

A queen-size mattress, averaging 60 inches wide by 80 inches in length, offers more space to move around. Before selecting a full-sized mattress, one should consider sleeping style and comfort needs.

Space

Full-sized mattresses are desirable in homes where room space is a premium. For example, in small studio apartments and older tenement building, it's not usual for bedrooms to be tiny.

A queen-size mattress averages 33 square feet compared to 28 square feet for a full, so a full-sized mattress takes up less room space. Additionally, a full-sized mattress is less cumbersome to carry up a narrow stairwell, commonly found in older apartment buildings.

Size of Sleeper

A full-sized mattress is ideal for an adolescent. However, those taller than 5-foot-5-inches might find a full too short. While not readily available, certain mattress retailers carry extra-long full-size mattresses. Measuring 84 inches, the extra-long full offers additional length and leg room for adults who like a full-sized mattress but don't like the shorter length.

Full Versus Twin

As compared to a twin-sized mattress, a full provides more sleeping space, especially if the sleeper is an adult or one who needs room to move at night. While a twin-sized mattress is cost effective, takes up little space and is easily transportable, it has limitations in terms of sleeping comfort. While a young child can sleep comfortably on a twin, an adult might find the mattress width constraining.