What is a Split King?

Finding the right mattress can be challenging—and when you add another person to the mix, it can feel nearly impossible. What should you do if you want a plush memory foam bed and your partner needs an ultra-firm surface? We recommend that you consider a split-king mattress so you both can get what you want.

A split king mattress is two twin XL mattresses placed next to each other on a king-size frame. Two twin XL mattresses have the same dimensions as a king-size bed, making this an excellent solution for couples who can’t agree on a single mattress. Here’s what you need to know if you’re considering a split king mattress. 

A split king mattress is a king-size mattress created by placing two twin XL mattresses next to one another. A split king has the same dimensions as a standard king-size bed, measuring 76 inches wide by 80 inches tall.

Split King Mattress Benefits

There are many benefits for couples who choose a split king mattress. Here’s why a split king might be the best option for you. 

Good for Couples with Different Preferences

Mattresses are rarely one-size-fits-all. Lightweight people, for example, may not need as much lumbar support as heavier people do. If you and your partner are different sizes, it’s possible that you’ll each need something different from your mattress. 

Couples may also disagree on mattress materials. Some people prefer bouncy beds that are easy to move around on, while others like to feel soft memory foam along their joints. 

With a split king mattress, both people can sleep on a mattress that suits their needs and preferences. However, I recommend choosing two mattresses that are the same height because the beds will line up next to each other on the same frame.

Pairs with Most Adjustable Bases

Adjustable bed frames can be extraordinarily helpful for sleep hygiene, especially if you or your loved one snores. Couples who sleep on a split king mattress with a dual-sided adjustable base can customize the mattress position. 

A wide shot of the Nolah adjustable base with the leg area raised

Research shows that elevating your upper body at night can alleviate snoring. So if you or your partner snores, you can independently adjust that mattress to an inclined position, helping you both get a better night’s sleep.   

Easier to Move 

Does your partner wake you up at night by getting out of bed or endlessly tossing and turning? When couples share a mattress, they’re often disturbed by one another’s movements, which can interrupt their sleep. 

Because split king mattresses are two separate beds, movement doesn’t travel from one side of the mattress to the other. With zero motion transfer, you and your partner may sleep better.

Split King Mattress Drawbacks

While there are many reasons couples may want a split king mattress, it’s not the right fit for everyone. Here are some of the reasons you might want to choose a different mattress size. 

Has Ridge in the Middle 

As we’ve explained earlier, a split king mattress is two twin XL mattresses placed next to one another. This means there isn’t a seamless surface. Even if each mattress is the same height, you can tell where one mattress ends and the other begins. Because of the midline ridge, split king beds aren’t as good for sex or cuddling as traditional king-size mattresses. 


A split king mattress costs more than a singular king mattress, making it the most expensive traditional mattress size. While the investment can pay off in comfort and sleep quality, the higher price point might make you consider sharing a singular mattress. 

Requires Two Fitted Sheets

With two mattresses comes two fitted sheets…meaning you’ll have to put on twice the number of fitted sheets every time you wash them. 

Casper Hyperlite fitted sheet


A split king-size mattress measures 76 inches wide by 80 inches long—the same dimensions as a king-size bed. If you have a small bedroom, you may need a smaller mattress. Many couples share a queen mattress because it’s 16 inches narrower than a king or split king. That difference can feel pretty substantial in smaller bedrooms.  

Best Bed Frames for Split King Mattresses

You can place a split king mattress on any king-size frame, but you get the greatest versatility with a split king adjustable base. We recommend an adjustable base if either of you snores or has acid reflux. A slight incline can help reduce snoring and reflux symptoms—and on a split king adjustable frame, only one person needs to do the adjusting. 

The Saatva Lineal base is both stylish and useful, and it should last at least 10 years. If you want something more affordable, you may want to consider the Nectar adjustable base

What to Look for in a Split King Mattress

When shopping for the best split king mattress, think about what you need to feel comfortable and sleep well. Here’s a breakdown of the most important factors to consider when looking for your ideal mattress.  


Firmness is the first thing most of us think of when looking for a new bed, and for good reason. Choosing the right firmness is essential for sleeping well and waking up without aches and pains. 

But what firmness is best?

For most of us, a medium-firm bed like the Nectar mattress offers the right balance of pressure relief and support. However, the best firmness level varies based on your sleeping position and body size.

Back sleepers typically prefer medium-firm beds, while side sleepers need softer beds that can alleviate pressure along the shoulders and hips. If you snooze on your side, you may like the Brooklyn Bedding Sedona Elite. Stomach sleepers need firm mattresses in order to maintain the proper spine alignment throughout the night. If you’re a stomach sleeper, you may want to consider the Plank Firm or Helix Twilight Luxe mattress. 

Your weight also influences how soft or firm a bed feels. Lightweight people don’t place as much pressure along a mattress’s surface, so beds often feel firmer to lightweight people. If you weigh under 130 lbs, you may need a softer-than-average bed. Heavy people who weigh more than 230 lbs usually need supportive, durable mattresses. There are excellent beds designed for bigger bodies, like the Titan Plus Luxe.  


Do you prefer a bouncy mattress or one that you can sink into? Knowing how you want your mattress to feel is essential for finding the best option. Here’s a breakdown of the different mattress types and how they feel.

  • Innerspring mattresses are springy and supportive. These mattresses feel very bouncy and are easy to move around on.
  • All-foam mattresses usually feel slow-moving and soft. They’re good options for people who want to sleep “inside” their bed, rather than on top of it.
  • Hybrid mattresses have coils at the bottom and foam layers on top. There’s a lot of variety in how these beds feel, but they tend to balance the benefits of all-foam and innerspring mattresses. Expect a little bounce with noticeable comforting cushion.
  • Latex mattresses usually feel responsive and cooling. 


If you struggle with night sweats, you aren’t alone. Sleeping hot is a common concern, and the mattress you sleep on can exacerbate or alleviate the issue. 

Generally, innerspring beds sleep the coolest, and memory foam beds trap the most body heat. However, companies have devised numerous ways to keep sleepers cool, ranging from breathable covers and coil layers to gel-infused foams. Take a look at our list of the best cooling mattresses for some options.

Edge Support

Edge support is one of those mattress features you don’t think about until you buy a mattress that doesn’t have it. Supportive edges allow couples to spread out and claim their own space—without feeling like they might roll off the mattress. 


What is the purpose of a split king mattress?

A split king mattress helps couples sleep better without sleeping in separate beds. On a split king, you and your partner each choose your ideal mattress and place them next to one another on a king-size bed frame. So, if you prefer different firmnesses or materials, you can both get what you need.

Can you feel the split in a split king bed?

Yes, you can feel the split in a split king bed—although how much you feel it depends on the mattresses you choose. Opt for beds with the same thickness to make the split less noticeable.

Is a split king the same as two twin XLs?

Yes, a split king is the same as two twin XL mattresses. In fact, it’s two twin XLs placed next to one another on a bed frame. Two twin XL mattresses pushed together have the same dimensions as a king-sized bed, 76 inches wide by 80 inches tall.

Nicole Gleichmann

Nicole Gleichmann is a freelance writer specializing in biology, sleep, and health. Before her career as a freelance writer, Nicole worked as a nutrition coach alongside fitness icon Thomas Delauer, helping people reach their health and fitness goals. When not at her computer, you’ll find Nicole hiking, traveling, and spending time with her new baby and two pups.