Mattress Sizes: King

Mattress Sizes: King

December 17, 2019

Author: Lisah

King mattresses are a great solution for the master bedroom, as the extra room can create a more luxurious sleep experience. Couples sleeping on a king mattress with different comfort preferences can choose to use two Twin XL mattresses in place of one king mattress. This way, each sleeper has a mattress to meet their specific comfort needs.

Serta produces a wide variety of king mattresses featuring both innerspring and all-foam support systems.

A Serta king mattress measures approximately 76″ x 79.5″. These measurements can vary by +/- 1/2″. Size availability varies by product and retailer. Mattress heights vary by product, so please see your retailer for information on specific model height.

Select retailers offer a special size called a California king mattress for select models, which measures approximately 72″ x 83.5″. Please see your local retailer about availability of Serta California king, or “Cal king”, mattresses.

Width x Length

Standard Size

38″ x 74.5″


38″ x 79.5″

Twin XL

53″ x 74.5″


60″ x 79.5″


76″ x 79.5″


72″ x 83.5″

California King