Twin mattresses (sometimes called "single" size) measure approximately 39"W x 75"L and are the smallest mattress size. They are the most affordable and compact mattress size, and are most often used for children's beds, daybeds and trundles. A standard twin size mattress is wide enough to accommodate many teen and adult sleepers, but generally will not be long enough for many adults. We offer innerspring, latex and memory foam twin mattresses at all price points and comfort levels.