Sometimes called a "Double" mattress. Wider than a twin, but still limits sleeping space for two adults.
Approx. width per person: 27"
Pros: Fits into smaller rooms. Sheets are less expensive than queen or king size.
Cons: Considered by many to be too narrow for two adults. At 75" in length, may be too short for some.
Longer and wider than a full, a queen is more accomodating for two adults. A good choice for smaller master bedrooms.
Approx. width per person: 30"
Pros: Better fit for two adults. Plenty of length for most adults. Bedding is easy to find.
Cons: Only slightly more sleeping width per person than a full. Some bedding is sold as "Full/Queen" and may not perfectly fit either size.