Bed size
North America
The sizes of mattresses use non-numeric labels such as a "king" or "full", but are defined in inches. Historically most beds were "twins" or "doubles" but in the mid-1940s larger mattresses were introduced by manufacturers. These were later standardised as "queen" and "king", and first made a significant impact on the market in the 1950s and 60s. Standard mattress depth ranges from the "standard" size of 9 inches (23 cm) to "high contour" of up to 13 inches (33 cm). Below are the standard ISPA widths and heights in the United States and Canada. U.S. bed sizes usually have a length of either 74 or 80 in (188 or 203 cm), while UK bed sizes usually have a length of either 75 or 78 in (191 or 198 cm). Widths also differ between the U.S. and UK standards.
Bed size-23