king vs split king mattress dimensions infographic

King vs. Split King: What’s the Difference?

You would be right if you guessed that the king size bed is the largest size mattress available. Because of its size, it’s a great pick for anyone who shares their bed with a partner, kids, and pets since it affords ample space for the whole gang.

Although there are variations on the king—including California, Alaskan, Wyoming, and Texas king sizes—the two most common are the standard king and the split king.

Is a king or split king mattress the right mattress size for you? Our split king vs. king guide will help you determine just that.

What is a split king?

A split king is the same size as a king, but instead of one single mattress, it’s actually two separate mattresses together on one frame.

king vs split king - split king mattress dimensions infographic

Split king dimensions

A split king mattress measures 76 inches wide by 80 inches long, the same dimensions as a king size bed. The difference: A split king consists of two side-by-side twin XL mattresses, each measuring 38 inches wide by 80 inches in length.


Why would you want your king size bed to be split down the middle? There are a few good reasons. Here are the top three benefits of a split king mattress:

  • Do you like it firm but your S.O. prefers a softer sleep surface? If you and your significant other have divergent opinions on what mattress comfort level feels best, then a split king mattress could be the answer. Getting a split king means you can choose two different firmnesses, so you each end up with what you want. If you pair the mattress with a split king adjustable base, this will give each of you the opportunity to raise your head and feet separately.
  • You won’t feel your partner moving while you sleep. A split king mattress eliminates motion transfer because you’re technically on two separate sleep surfaces. This is a particularly good feature if you or your partner is a combination sleeper—someone who switches positions throughout the night. Being on two separate mattresses means you won’t disturb each other if you move around while you snooze.
  • It’s easier to move than a standard king mattress. A king size bed is tough to navigate through tight spaces. Since it is so big, you may not be able to get it up a narrow staircase or around corners. That’s when you can consider a split king, which gets you the same size sleep surface but in the form of two twin XL mattresses, which are much easier to move.

Our Best Split King Mattress for Couples

Solaire Precision Adjustable Air

Featuring 50 precise firmness settings on each side of the bed for personal customization. Talalay latex and gel-infused memory foam layers provide luxury comfort and support.



A split king mattress isn’t without its drawbacks. Before buying one, keep this in mind:

  • The split in the middle of the mattress can be inconvenient for couples who like to cuddle. You and your partner will be separated by the division in the middle of the mattress.
  • Split kings require special sheets, consisting of a single top bed sheet that covers both mattresses, and two fitted sheets that individually cover each mattress. While you can find split king sheet sets, they aren’t as common as standard king sheets. (Here’s what you need to know about special mattress sizes before you buy one.)
  • It can be more expensive than a standard king. Depending on where you buy your mattress, you may end up spending a few hundred dollars more for a split king mattress vs. a regular king.

king vs split king - king size mattress dimensions infographic

King mattress size

The standard king mattress measures 76 inches wide by 80 inches long.


To help you decide between a king vs. split king, we’ve rounded up the top four benefits of choosing a standard king size mattress:

  • A king size bed provides more room for couples—without the division down the middle that comes with a split king. “Most people would agree that the biggest advantage in getting a king size bed is more generous room for you and your partner,” says Mary Brennan, interior designer and founder of House of Fine Design in New Jersey. “Not only is it just more comfortable, but in particular, if one person is more of a restless sleeper or a light sleeper, the added sleep space helps keep disturbing the other to a minimum.”
  • Due to its large size, a king mattress allows plenty of space for children and pets.
  • Its larger size can help fill empty space in a large-size bedroom.
  • A king offers extra space for other activities besides sleep and sex, such as working or watching TV from bed.

Our Best King Size Mattresses

Saatva Classic

Our flagship luxury mattress is expertly engineered with coil-on-coil construction for durability, a layer of memory foam for enhanced back support, and a cushiony Euro pillow top for extra comfort.



While there are a lot of positives to getting a king size mattress, there are some drawbacks too. Here are the four biggest reasons to not get a king bed:

  • It’s too much work for a solo sleeper. The king isn’t practical for solo sleepers because it’s a lot of bed for one person to have to make up alone. “A king size is a bit more effort when it comes to making and dressing the bed since it is so much larger,” says Brennan.
  • A king size bed takes up a lot of space. It won’t fit in studio apartments or small bedrooms. The ideal bedroom size for a king size bed is 14 feet by 19 feet, although it will technically fit inside a room as small as 10 feet by 12 feet.
  • Since they’re so large, they can be tough to navigate. You may find yourself unable to fit it up stairs or get it through your front doorway. (This is when you’d want to consider a split king instead.)
  • Because a king size bed is the largest bed size, it’s a higher price than other mattress sizes—and you’ll have to spend more on things like a headboard and bedding.

Difference between split king and king

A split king mattress isn’t bigger than a king—in fact, they have the same dimensions. They do have a few key differences, however. We’ve put together this handy comparison chart to help make your choice between the two easier.

Comparison Split King King
Dimensions 76″ x 80″ (two twin XLs side-by-side) 76″ x 80″ (one mattress)
Min. recommended room size 10′ x 12′ 10′ x 12′
Who it’s best for Couples with different sleep preferences Couples who want a generous amount of space
Benefits Ability to choose two different firmnesses

You can raise head and feet separately when paired with adjustable base

You won’t feel partner moving during sleep

Easier to move than a standard king
Provides the most room for couples (without division in center)

Plenty of room for kids and pets

Large size can help fill space in big bedroom

Offers extra space for activities like reading and watching TV from bed
Drawbacks Split in middle can be inconvenient for couples who like to cuddle

Requires special sheets

Can be more expensive than standard king
Too much work for solo sleepers and won’t fit in small bedrooms

Can be hard to navigate up stairs and into doorways

More expensive than other standard mattress sizes

Foundations for a split king

Both standard king size mattresses and split kings can generally be paired with several foundation types, from a traditional box spring foundation to an adjustable base to a platform bed.

Pair These Foundations with a King or Split King Mattress

Saatva Foundation

Provides optimal support for your mattress. Handcrafted from North American spruce, our foundation is more durable than a traditional box spring.


How do they work?

Split king foundations are split down the middle for ease of delivery. This is to ensure the foundation can be moved around tight doorways, staircases, and narrow corners. The two sections of the foundation are pushed together to make one unit.

A split foundation is standard on all king size variations, whether a standard king, California king, or split king. A single-unit king foundation would simply be too large and difficult to maneuver.

One difference in foundations between kings and split kings is adjustability. If you pair a split king mattress with an adjustable base, you can raise and lower your head and feet separately on each side of the bed since the mattress is comprised of two separate surfaces. With a standard king, you can only raise and lower head and feet together.

One issue with separate mattresses is that they can occasionally shift on the foundation. To keep that from happening, the easiest thing you can do is place a non-slip mattress pad between your mattress and the fondation to keep to keep the two twin XLs from sliding around.

Still not sure which type of king size bed is right for you? Consult our guide to California king vs. king mattresses for help determining your ideal mattress size.