Detailed Mattress Comparison

A twin XL mattress and a split king are the same dimensions at 38 inches wide and 80 inches long. However, a split king is made of two twin XL mattresses placed next to each other on a king size bed and is great for couples with different sleeping preferences. Essentially, a split king is a king size mattress split in half and a twin XL mattress is 5 inches longer than the standard twin-size mattress. 

In this article, you’ll get to know the difference between twin XL and split king in detail so that you can pick one as per your sleeping preferences.

ParametersTwin XL MattressSplit King Mattress
IN:38″ X 80″ X 11”
FT:3.25 X 6.67 X 0.92
CM:99.06 X 203.2 X 27.94
IN:38″ X 80″ X 11” (Each Sleeper)
FT:6.33 X 6.66 X 0.92
CM:93.04 X 203.2 X 27.94
Bed Size38 X 80 inches76 X 80 inches
Recommended Room size8 X 10 feet 12 X 12 feet
Comfortably Fits
  • Single Sleeper
  • Single sleeper
  • Couples with different sleeping preferences

What is a Twin XL Mattress?

A twin XL mattress is 38 inches wide and 80 inches long. It’s the same width as a standard twin mattress but is 5 inches longer. The extra inches give more legroom to tall sleepers. Twin XL beds are a common choice for college dormitories and smaller apartments. With the extra legroom, it allows more length while being easy to use in compact rooms. 

Also Read: <Link to Twin XL guide>


  • Ideal for teenagers or single adults
  • 5 inches  longer than standard twin mattress
  • Affordable and easily available
  • Suitable for small rooms


  • Only accommodates single sleepers 
  • Not enough space for individuals who like to sprawl People who like more sleeping space may feel cramped 

What is a Split King Mattress?

A split king mattress, as the name suggests, is a standard king mattress split in half. Each side of a split king mattress is the same size as a twin XL mattress. Split king mattresses allow couples to customize their side of the bed because of the split in the middle.  In a split king, each sleeper enjoys 38 by 80 inches of personal space. A split king mattress is used with an adjustable bed. To know more about adjustable frames, click here

Also Read: Split King Mattress – A Mattress Guide


  • Ideal for couples whose sleep preferences don’t match
  • Almost zero motion transfer 
  • Exclusive personal space of each sleeper
  • Adjustable base


  • Assembling is a little complicated
  • Expensive than a standard king mattress

Split King vs Twin XL — What should you consider before buying?

Room Size

A room that is at least 12 by 12 feet can comfortably accommodate a king or a split king adjustable bed as they are the same dimensions. It’s a great option for a master bedroom. A twin XL fits comfortably in a room that is at least 8 by 10 feet. It is a great option for single sleepers with restricted spaces like a dorm room, a studio apartment, or a small bedroom.

Sleeping Partner 

If you share your bed with a partner but would like to have separate mattresses customized to your preference, a split king is the best choice. A twin XL can be a great choice for teenagers or an adult with restricted sleeping space. It cannot accommodate more than one individual and can be cramped for an adult. 

Bed Size

A split king mattress needs an adjustable king bed that is split in the middle. Each side of the split king is 38 by 80 inches and is 76 inches by 80 inches when put together. Each partner can thereafter choose the settings for their side of the bed. 

A twin XL fits well on a bed that is 38 by 80 inches. A twin XL cannot be used on a standard twin bed as it is 5 inches longer than a standard twin mattress and the mattress may hang from one end.


Twin XL is preferred by tall sleepers who sleep alone. It offers 5 inches extra than a twin mattress making it suitable for teens or adults taller than 6 feet.  A Split king is the same length as a twin XL and offers enough space for individuals taller than 6 feet. 


A split king mattress costs more than a twin XL as it is meant for two people or a couple. A twin XL can cost $569 or more while a split king costs more than a standard king mattress which costs around $999. Because a split king mattress needs split or separate bed frames it can be costlier and not so easily available in the market. 

More on Mattress Sizes

Choosing Between Twin XL vs Split King Bed 

In short: a split king is two twin XL  mattresses joined together. So, the key distinction is that one is twice as wide as the other. A split king is meant for couples who need personalized sleeping spaces while a twin XL is meant for a single teen or adult. To make it easier for you, we’ve curated a comparison guide to make the best decision. 

How we compare to other Brands?

We offer a 365-day trial period and a warranty that lasts forever! If you don’t believe us go ahead and compare our offer to other brands. Apart from being one of the largest mattress sellers in the United States, we give you 9 reasons why nectar may be your best and the last mattress you purchase.

Sleep Trial Warranty Free Shipping * Free Return 2 Free Pillows Free Sheets Free Mattress Protector Price (Queen) Total Price
Nectar 365 Nights Forever Warranty™ check check check check check $799 $799 Shop Mattress
Casper 100 Nights 10 Years check check $178 $139 $95 $1,095 *$1,507+
Purple 100 Nights 10 Years check check $196 check $99 $1,149 *$1,444+
Shop Mattress *Price reflects the subtotal of mattress protector, sheets and two pillows (Single pillow for twin/twinxl) compared to the current promotion on Nectar. Additional shipping fees may apply in AK and HI. Price may not reflect any current promotions or discounts. Last Updated: Mar 2021.

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How to choose between split king vs king size mattress?

If you sleep with your partner and have different sleep styles or different mattress preferences, the split king is a suitable option. In split king, each sleeper enjoys 38 by 80 inches of personal space.  Personalisation within the same bed is not possible in a standard king. 

When is a twin XL better than a twin?

When you or your teen is a tall fast-growing individual a twin Xl may be the wiser choice. A twin XL mattress is 38 inches by 80 inches — about the same size as a standard twin bed, but 5 inches longer. The extra length makes it an excellent choice for tall sleepers giving them more legroom. 

Do two twin XL beds make a California king mattress?

No. A traditional king mattress can be made from two twin XL beds. A California king mattress is 72 inches by 84 inches, while two twin XL mattresses mounted side by side are 76 inches by 80 inches (standard king size).

Is a king size bed the same dimensions as two twin mattresses?

No. Two twin XL mattresses, when put together, can make a king-size bed. It is called a split king mattress, where two people enjoy personal sleeping space as per their preferences.