The primary differences between king and queen-size beds are their dimensions and their use throughout different areas of the world. The queen-size bed is the more common of the two by a significant margin, but the classification of each size is used differently in different countries. Though the understanding of what a "king-size bed" refers to in North America is ubiquitous, the specific dimensions of it differ by country.
Bed Dimensions in the United States
The fundamental difference between king and queen beds are their dimensions, specifically the width of the mattresses. A standard queen-size bed is 60 inches wide and 80 inches long, whereas a standard King-size bed is 76 inches wide and 80 inches long.
Regulated bed dimensions in the U.S. also recognise the California king and California queen mattress sizes. The California queen mattress measures 60 inches wide and 84 inches long, and the California king measures 72 inches wide and 84 inches long. This system, much less common than the standard king and queen, provides extra length for taller people, though the California king mattress is slightly narrower than the standard king. Other rarer bed sizes include the super queen mattress, measuring 66 inches wide and 80 inches long as well as being slightly thicker than the standard queen, and the grand king mattress, measuring 80 inches wide and 94 inches long.
United Kingdom Sizing
The standard United Kingdom sizing for beds does not include a queen-sized mattress, but rather uses a king and a super king. The UK king mattress measures 60 inches wide and 78 inches long, and the super King 72 inches wide and 78 inches long.
King Beds and Box Springs
King-size beds are limited in use to such a degree that obtaining a king-size boxspring can be difficult. It is common practice to use two smaller boxsprings together to support a single king-size mattress.