Is King size the largest mattress?

A king is the largest mattress that is commonly manufactured, though a California king has slightly different dimensions if the buyer is looking for a longer bed, according to the Bedding Experts. However, certain companies, such as Selectabed, make beds that are much larger.

A standard king-size bed is 80 inches long by 76 inches wide, while a California king is 84 inches long by 72 inches wide, according to Sleep Experts. Companies such as Selectabed make much larger beds based on custom orders, with beds anywhere from 96 inches wide by 108 inches long to 120 inches wide by 144 inches long, including custom shapes to fit particular spaces.