On a bed-sizing chart, a 3/4 size bed falls in between a twin-size bed and a double/full-size bed. 3/4 size beds are not considered to be a "standard size" in 2010.
The standard width for a 3/4 size bed is 48 inches, compared to 39 inches for a twin and 54 inches for a double. The standard length for a 3/4 size mattress is 75 inches, which is the same length as a twin or a double. An extra-long 3/4 size mattress is 80 inches long.
3/4 size bed frames are often difficult to find, although they can be purchased online from certain dealers. 3/4 size bed frames can also be found as antiques, and it is possible to adapt a full-size bed frame to fit a 3/4 size headboard with converter plates.
The 3/4 size mattress is no longer on the list of "U.S. Standard Mattress" sizes. However, some mattress companies do offer custom-made 3/4 size mattresses.