Detailed Mattress Comparison

As the name suggests, a split king mattress is a king mattress split in half. A king size mattress is twice as wide as a split king. While both are 80 inches long and 76 inches wide, a split king mattress is generally used in combinations of two to form a king mattress.

The standard king is 76 inches wide and the split king is 38 inches wide. A Split king is used with an adjustable bed which allows each partner to have their own position in the adjustable bed. 

The difference between a split king mattress vs king mattress is that a king-size mattress provides plenty of personal space for couples, while a split king mattress allows you to personalize your side of the bed. But there are still a few things to consider before you buy one for yourself.

ParametersStandard King MattressSplit King Mattress
IN:76″ X 80″ X 11”
FT:6.33 X 6.66 X 0.92
CM:193.04 X 203.2 X 27.94
IN:38″ X 80″ X 11” (Each Sleeper)
FT:3.16 X 6.66 X 0.92
CM:96.52 X 203.2 X 27.94
Bed Size76 X 80 inches38 X 80 inches
Recommended Room size12 X 12 feet12 X 12 feet
Comfortably Fits
  • Couples with a child or a pet
  • Couples with different sleeping preferences

What is a King Size Mattress?

A standard king-size mattress is 76 inches wide and 80 inches long. A king-size bed is the same dimensions as two twin XL mattresses placed side by side. 

Among all the mattress sizes, the king size is the most popular size on the market for large families and big rooms. It fits well in a master bedroom or rooms bigger than 12 by 12 feet. A king size bed is the perfect size for couples who share their bed with kids or pets.

Also Read: King Size Bed Dimensions – A Comparison Guide 


  • Perfect for couples who share the bed with kids
  • Ideal for spacious bedrooms


  • Expensive
  • Too wide for restricted spaces
  • Hard to move because of weight 

What is a Split King Mattress?

A split king bed measures 38 inches by 80 inches. It measures the same as a Twin XL and can be used as a single unit or can be combined to form a full king bed. When put together, two split king mattresses allow couples to personalize their side of the bed as per their needs and avoid disturbance during sleep. 

A Split king is used with an adjustable bed and allows each partner to choose their own position in the adjustable bed. Know more about adjustable beds here.

Also Read: Split King Mattress – A Mattress Guide


  • Perfect for couples whose sleep preferences don’t match
  • No motion transfer 
  • Exclusive personal space of each sleeper
  • Adjustable base


  • Assembling the bed is complicated
  • Expensive than a standard king mattress
  • The gap may cause discomfort 

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

Room Size

A king-size is a great option for master bedrooms. Your bedroom should be at least 14 x 19 feet in size to accommodate a king and leave enough room for other furniture. 

When two split kings are put together they are the exact same dimensions as a standard king size mattress. Split king mattresses will fit comfortably in a room that is 14 x 19 feet as well. When used alone the split king is the same as a twin XL and can be fit into smaller rooms. 

Sleeping Partner

Both king and split king provide ample space for couples. The only difference between both mattresses is that a split king caters to the each partner’s specific needs. 

A King size is preferred among couples who like to cuddle at night and share the same sleep preferences. Whereas a split king works best for couples who have different sleeping styles and preferences, allowing them to customize their side of the bed as per their needs. 

Cost and Accessibility  

A standard king size mattress is cheaper than a split king mattress. If you’re on a limited budget, choosing a standard king mattress is advisable. It is readily available in the market and is less expensive than the split king. However, if there’s no budget constraint and your partner and you have different sleeping preferences then a split king mattress is the perfect solution.

Bed Size

A king size mattress needs a bed size that is at least 76 inches wide and 80 inches long. A split king mattress requires the exact same bed size as a king because the dimensions are similar. If you and your partner also require different bed frames, then consider using a split king bed frame along with the mattress.

Height and Sleeping Position

A person of average height or taller than average can both sleep comfortably on either of the mattresses as they are approximately 6.6 feet long. 

If you sleep on your stomach or prefer a fetal position while sleeping, a king is the better option for you. Sleeping on the gap near the split of the split king bed could cause discomfort while stretching out at night. On the other hand, a king or full-size mattress would give you that extra sleep space comfortably.

More on Mattress Sizes

Choosing Between King vs Split King Mattress 

Both king and split king are great options for a master bedroom. Your choice depends on your and your partner’s personal preference. 

While a king-size is an excellent option because it provides sprawling space for couples, a split king caters to the personal preferences of both partners without compromising on the quality of sleep.

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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So long sleepless nights!


Are split twin and split king the same?

No. A split king mattress is the same as two twin XL mattresses put together, not two twins. A split king gives extra length compared to a twin mattress. 

Are two twin XL mattresses the same as a split king?

Yes, two twin XL mattresses put side by side are the same as a split king. 

What other options do I have in a split mattress?

Other mattress options that work well for couples include flippable mattresses, manually adjustable firmness mattresses, and electronically controlled adjustable firmness mattresses.

Want to know more about other foam mattress sizes?

Here’s a quick comparison guide that will compare all sizes like the queen size mattress, the full size bed, the twin size mattress and all other standard mattress sizes to help you make the best decision.

Does nectar sleep have memory foam mattresses?

Yes, you can check out our range of memory foam mattresses