A three-quarter bed measures 48 inches wide by 75 inches long. Three-quarter beds are the intermediate size between a full bed and a twin bed. Both twin and full beds are 75 inches long, but twin beds are 39 inches wide, while full beds are 54 inches wide.
Three-quarter beds are generally older bed frames, and it can be difficult to find bedding to fit them. The three-quarter bed is sometimes confused with the antique bed. Both are 48 inches wide, but the antique bed is three inches shorter. These bed size standards help consumers, retailers and manufacturers communicate about mattress and sheet fittings.