A daybed is a functional space saver that combines a sofa with a bed. It uses one size of mattress, a twin size, which limits the choices as far as the number of people who can comfortably sleep on it. A daybed also often has an optional trundle underneath it that uses the same size mattress.
Daybed Mattress Size
Aside from the mattresses used in baby cribs, the twin mattress offers the smallest dimensions. It measures 39 inches across and 75 inches in length. Twin mattresses, which are offered in various thicknesses, are normally about 8 inches thick for a daybed. Daybed frames often have stylish frames, and a mattress that is not overly thick keeps from blocking any view of the daybed itself. The length of the mattress probably won't reach all the way to the frame edges, which allows you room for the bedding on top of it.
Mattress Size Limitations
Because they are, at their core, space savers, daybeds don't offer the most sleeping space. A twin size mattress and bed is often the choice for use by young children before they hit a growth spurt and for use in a home's guest room. The width of 39 inches is basically suitable for only one sleeper but might allow enough room for a parent to lie beside a small child, although space will be cramped. The 75-inch length is not comfortable for most taller adults, especially men.
Covering the Mattress
Daybed mattresses can be draped with a cover during the day as an alternative to bedding, which gives the daybed an attractive, sofa-like look. For sleeping, comforter sets are often placed on the daybed and include a comforter, three shams and sometimes a bed skirt, which hangs below the mattress, hovering down to a point just above the floor. The comforter is usually 52 inches in width and 99 inches in length, compared to the normal 62-inch width and 86-inch length of twin comforters.
Adding the Trundle
Although daybed mattresses are always a twin size, there is a way to make the bed larger. The optional trundle underneath the daybed can sometimes add to the daybed's mattress dimensions. The trundle mattress either slides straight out or pops up, elevating to the same level as the daybed mattress. With the pop-up type of trundle, the two mattresses end up lying side by side, which basically creates a combined width measurement that equals that of one king size mattress, which is about 76 inches wide.