Twin XL Mattress Dimensions Size Guide

Twin XL Mattress Dimensions Size Guide

April 22, 2022

Author: Lisah

As you go through the process of choosing the right mattress for you or a loved one you’ll be asking yourself all sorts of questions you’re not sure the answer to, which honestly is probably why you are here. Below in the Twin XL Mattress Dimensions Guide you will find the answers to some of the very questions you have been asking yourself while mattress shopping. If you don’t please reach out to our customer support as we are here to ensure you get the mattress size that is right for you.


Approximate Serta Twin XL Dimensions/Measurements
Inches: 38” x 79.5”
Feet: 3’ 2” x 6’ 7.5”
Square Inches: 3,021
Square Feet: 21


Why would I choose a Twin XL mattress?
You would choose a Twin XL mattress if you are a single adult living in a very small space like a studio apartment, a college student staying in a dorm, have an extra tall child upgrading to their first big bed or want/have a split king set up.

Is a Twin XL bed the same length as a full sized bed?
No. A Twin XL is actually approximately 5 inches longer than a Full size. But a Full is 15 inches wider than a Twin & Twin XL.

What is the difference between a Twin and a Twin XL mattress?
The only real difference between a Twin and a Twin XL is about 5 inches in length. Twin XL is longer than a Twin.

Will a twin XL mattress fit a twin bedframe?
No. Despite the difference in length is only about five inches between a Twin and Twin XL, the Twin XL mattress will not fit into a standard sized twin bed frame because it will be too long.

Serta Twin XL Recommendations

Consider this comfy mattress in a box option if you are looking for a child or even bunk bed or daybed options.
Serta Perfect Sleeper Bed

Check out this cooling, supportive option if you are looking for an older child or college student.
Serta iComfort Bed

Check out this cooling, supportive option if you are looking for yourself.
Serta iComfort Hybrid Bed

Twin XL Mattress Size Dimensions Visual

Width x Length Standard Size
38″ x 74.5″ Twin
38″ x 79.5″ Twin XL
53″ x 74.5″ Full
60″ x 79.5″ Queen
76″ x 79.5″ King
72″ x 83.5″ California King


National Sleep Foundation’s logo, name, materials and/or insights used under license from NSF in exchange for Serta’s financial support of NSF’s sleep research and educational activities.

The Consumer’s Digest Best Buy seal, editorial review text, references to the editorial review, and Consumer’s Digest Best Buy rating are registered certification marks and trademarks of Consumers Digest Communications, LLC used under paid license. For award information, visit

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