Mattress Guides

King vs Split King: Which is Best For You?

By Carl Johnsen, August 24, 2022

King and split king mattresses are the two largest mattresses on the market, but actually, they’re the same size. What makes the two beds different is a king is a single mattress, while a split king is two mattresses.

Both king and split kings are a great choice for couples, co-sleepers, and individuals who just want lots of space to themselves. Given that king and split kings are so similar, it can be difficult to decide which is best for you.

Our article will go over the similarities and differences between a king versus split king mattress.

What’s a King Mattress?

King mattresses, also called Eastern kings, are 76 inches wide and 80 inches long. With a king mattress, couples get ample personal space and single sleepers have lots of room to toss and turn.

Since a king size mattress is so large, it’s also the most expensive standard mattress size. Eastern king mattresses can cost between $750 to over $4000 depending on the mattress’s construction and any special materials or technologies added.

Advantages of a King Mattress

  • Provides lots of space for couples and co-sleepers
  • Suitable for large master bedrooms
  • Largest mattress size

Drawbacks of a King Mattress

  • Requires a bedroom measuring at least 10 by 12 feet
  • Difficult and heavy to transport
  • Expensive compared to smaller mattress sizes

What’s a Split King Mattress?

A split king, or divided king, is the same size as an Eastern king mattress, but a split king is divided into two mattresses. Split kings are 76 inches wide and 80 inches long altogether, but the two individual mattresses are 38 inches wide and 80 inches long, or the equivalent of a twin XL size mattress. For reference, twin XL mattresses are 5 inches longer than a standard twin size mattress.

Mattress companies designed split kings with couples in mind. With a split king, couples can have mattresses with different firmnesses. For example, if you need a soft mattress, but your partner needs a firm mattress, a split king is perfect.

Couples can also get a split adjustable bed frame and alter the incline on their side of the bed. And since there are two separate beds, couples won’t need to worry about motion transfer when shifting or getting out of bed.

Split king mattresses are usually the same cost as king mattresses, but some brands might charge $100 or so more for a split king versus a king.

Advantages of a Split King Mattress

  • Accommodates couples with different firmness preferences
  • No motion transfer from one mattress to the next
  • Mattresses move independently on adjustable bed bases
  • Easy to transport two separate, small mattresses

Drawbacks of a Split King Mattress

  • Noticeable gap between the two mattresses
  • Unnecessary for single sleepers
  • Requires two sets of sheets
  • Occasionally costlier than standard king mattresses

Other Large Mattress Sizes

If a king or split king mattress doesn’t seem to fit your needs or living space, take a look at some similar types of mattresses: California king and queen size mattresses.

California King

California king mattresses are 72 inches wide and 84 inches long, so they’re a bit narrower and longer than your standard king or split king mattresses. Cal king mattresses also come in a split king variation called a split California king.

We recommend a California king size mattress for tall adults, couples, or adults with narrow master bedrooms.

Interested in learning more about the differences between Cal king and king mattresses? Check out our other comparison guide.


Queen mattresses are 60 inches wide and 80 inches long and are the most popular mattress size among both couples and single adult sleepers. Queen mattresses are the smallest mattress size we recommend for couples. Compared to a king or split king, a queen size mattress is a bit narrow, but it should still be comfortable for two sleepers.

Queen mattresses are a good option for couples, solo sleepers, and work well in guest rooms.

Interested in learning more about the differences between queen and king size mattresses? Check out our next comparison guide.


How do you keep a split king bed together?

Most split king mattresses come with an iron plate connector to keep the two beds together. If not, place a non-split mattress pad or tap between your mattress and the bed frame or foundation.

Another option is to use a bed frame with a high enough railing to keep the two mattresses in place.

Is a split king mattress uncomfortable?

The crater between the two twin XL mattresses is reasonable to be concerned about as it may make you feel too separated from your partner. However, the divide won’t cause sinking toward the center of the mattress.

Use foam gap fillers in between the two mattresses to improve the transition between the two mattresses. There’s the possibility you’ll feel the gap filler beneath you, but even so, it shouldn’t affect your comfort.

Can I put two twin XL beds together?

Alone, twin XL mattresses work well for college dorm rooms, apartments, and bunk beds, but pushed together, they function the same as a split king bed. After all, split king beds are just two twin XL mattresses. You can buy a split king mattress or purchase two twin XL mattresses separately and set them up as you would a split king.

You can tuck the two twin XL mattresses into a king size bed frame or use a non-slip pad to keep the two beds together. We suggest using a foam gap filler between the two mattresses to make the mattress’s surface more uniform.

What kind of sheets do you use for a split king bed?

For a split king size mattress, you must use two twin XL fitted sheets for the individual mattress, then a flat king sheet on top. Split king sheet sets come with the necessary fitted sheets and flat sheets, so you won’t need to go and buy separate sets. Some people may prefer using all twin XL bedding, but it’s not necessary.

Is there a bed bigger than a king or split king?

The king is the largest standard size mattress, but you can find oversized mattresses at specialty or custom mattress stores. The Wyoming king is 84 inches wide and 84 inches long, the Texas king is 80 inches wide and 98 inches long, and the Alaskan king is 108 inches wide and 108 inches long.

These oversized mattresses are rather rare and unnecessary since one or two people couldn’t use up all that space. Since these beds are so large, they only fit in incredibly large bedrooms. They’re also quite expensive both because they’re rare and because they contain lots of materials.

Is a King or Split King Best For You?

Although king mattresses and split king mattresses have the same dimensions, split kings are best for couples with different firmness or incline needs. Single adults don’t need the dual-mattress construction since it’s primarily for people sharing a bed. Couples with similar firmness needs and solo sleepers will likely prefer a standard king over a split king.

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