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Standard Bed Sizes – Furniture Facts

As one searches for beds to place in the master bedroom, guest bedroom, or kid’s rooms, they run across a myriad of different sizes to deal with. The purpose of this fact sheet is to identify to the buyer the different sizes and options available in beds manufactured in the first half of the 20th Century, such that an informed decision may be reached regarding the correct size piece desired.

Standard American Bed Sizes.

Somewhat surprisingly, American furniture manufacturers actually began standardizing bed sizes shortly after the Civil War, around 1870. At that time, bed and mattress manufacturers agreed upon standard sizes for a single (also referred to as a “twin”) and double (also referred to as a “full”) bed. By doing so, consumers could purchase beds and mattresses from different retailers around the country secure in the knowledge they would fit one another. This standardization replaced the previous requirement of consumers to have both beds and mattresses custom made.

The difference between the standard sizes of 1870 and those of today is the invention of “box springs” in the 1910’s. That is, prior to the development of box springs, the mattress was placed on top of something laying over the rails of the bed. Sometimes this would be rope tied from one rail to the other, while others would use slats or a sheet of wood laid across the top of the rails. With the invention of box springs, bed manufacturers had to move the distance or space between the rails and the headboard and footboard by a few inches so that the box springs could drop down inside the rails where they rest on slats. Thus, while the standardized dimensions did not change, the widths before the 1910’s were to the OUTER edges of the bedrails and since the 1910’s are to the INSIDES of the bedrails.

Single and double size beds were joined sometime around the 1920’s by the “3/4” size bed. Unfortunately, manufacturers on the east and west coasts would not agree upon an industry standard for the “3/4” size after they had already begun manufacturing them. Thus, they may be found in two slightly different widths.

The queen and king sizes began in the late 1950’s. The queen size bed was initially designed to be a replacement for the full or double bed – an idea which never came to fruition. The big difference in the development of queen and king size beds was the length: 80 inches. So that finally, people who were 72” or taller would no longer hit their heads against the headboard or have their feet dangling over the footboard while sleeping. [A notable difference given the ever-increasing average height of Americans.]

Accordingly, manufacturers also made an 80-inch length twin bed, called by different retailers as a “king twin”, “extended twin”, “long twin”, “extra length twin”, etc. The idea was that the 80-inch twin, queen, and king would supplant the 74” twin and full as American standards. However, the American public’s demand for 74” twin and full size beds (ideal for smaller size bedrooms) did not diminish, so that all five sizes are available as an industry standard today.

Initially, kings and queens were made with a headboard only, which was fastened to a free-standing metal bed frame. But by 1970, a trend was seen towards the manufacture of both a headboard and a footboard.


Any full size bed can be converted to queen, and any pair of twins can be converted to a king size bed. 80-inch conversion rails on the market with either the standard double hooks or bolt-on mounts replace the original 74” rails to make such conversions. The “secret to success” in making conversions is to find beds which can be converted without looking odd.Some full size beds are not much more than 54 inches wide, leaving a queen box spring and mattress protruding three inches on either side of the headboard and footboard. Others are as much as 58” wide, where the addition of a dust ruffle and comforter precludes the one inch extending beyond the headboard/footboard from being noticeable. And in the case of converting twins to kings, posters in the center of the headboard and footboard are obviously not the choice to make. A discerning eye towards the existing shape of the twin beds can make a selection which will look like a king size bed, and not just two twins bolted together.

Hopefully, the data contained herein provides the purchaser the ability to make an informed decision regarding the specific bed required to meet a specific need.