One of the most important factors in achieving a better nights sleep is comfort, with this in mind it is important to consider the amount of actual sleep space you will have available on your new mattress. In general, the mattress should be longer and wider than the amount of space you or you and your sleeping partner take up when laying on it. For two adults it is recommended to sleep on a queen or king size.
The following illustrations are a general guide to help you make the best decision.
Twin 39''x 75'' (inches)
Twin size is generally made to accommodate one child or one adult sleeper. On occasion when you need to lay with your child it should accommodate, but will be a bit crowded. If you are a taller adult you may want to consider a twin-XL which will give you added length. (see below). Twin (also referred to a ‘single’) is great for smaller guest spaces, bunkbeds, and daybeds.
Twin-XL 39''x 80'' (inches)
Twin-XL (Extra-Long) is 5 inches in length longer than the standard twin. This size is great for taller youth or adults. Twin-XL is the same length as a queen or king, In fact two of them side by side equals a king.
Full 54''x 75'' (inches)
Full or also known as a ‘double/standard’ was commonly used for two adults 30 - 40 years ago when the homes and bedrooms were built much smaller. Now it is usually purchased for single person use and sometimes smaller guest rooms. It is a tight fit for two adults and the same length as a twin. Two adults sleeping on a full size is equivalent to each person sleeping on a crib mattress (27 inches of sleep space). Most people with a sleeping partner opt for the queen size. Full can sometimes be special ordered in extra long.
Queen 60''x 80'' (inches)
Queen is the most popular size sold. Great for two adults that want to save living space in their master bedroom and great for single use for those who just like to stretch out.
King 76''x 80'' (inches)
King (also known as an eastern king) is the same length as a queen but much wider (16 inches). If you have the space it offers the most room for couples. King size beds are also great if you have kids or pets who like to share your bed. For very tall people you can also special order a Cal-King which is a 72'' x 84''.