Measuring 54” in width and 74” in length, the Full size mattress, often called a double, is best for a single sleeper who has outgrown a Twin. Generally, we don’t recommend a Full size bed for two sleepers, as a Full cut in half is equal in width to a crib size mattress. For a single sleeper with a small sleep space, a Full is an excellent option. Now that you know the size mattress you prefer, shop below by Brand, Comfort Level, or Type to find the perfect mattress for you.