Best Split King Size Mattress (2023): Reviews and Buyer’s Guide

When it comes to sleep, the surface we find most comfortable depends on our body type and sleep habits. Even the best mattresses are not one-size-fits-all. A lightweight side sleeper may find a softer mattress more comfortable. A heavier back sleeper will prefer something firmer. But for couples with different preferences, it can often be difficult to decide on a firmness level that suits you both. That’s where a split king size mattress can help.

Once you are ready to upgrade to a king-size mattress, opting for a split king allows you and your spouse to select the firmness for each side of the bed. With a split king, you can each choose the comfort level most suited to your individual needs. To help you select the best split king mattress, we have reviewed several high-quality options. Plus, we have included some points to keep in mind as you shop.

If you are interested in pairing your new split king with an adjustable base, we have also included reviews of two of the most advanced bed frames on the market.

Best Split King Size Mattresses

Amerisleep is an innovative brand making great strides in mattress technology. They offer a line of memory foam and hybrid mattresses. Each of their mattresses are designed with a specific firmness in mind. They make it easy for you to select the right mattress for optimal support and pressure relief.

Of their impressive selection, we recommend the AS3 mattress. This is our favorite option because it offers a universal comfort. The AS3 is a true medium on the firmness scale and is suitable for combination sleepers, side sleepers, and back sleepers.

It is soft enough to cradle the body, but it also has the perfect level of responsiveness to prevent sinking. When the joints are cushioned and the spine is resting in a neutral position, you will be able to find deep, restorative sleep.

The layers of the AS3 do all this and more! The soft, lightweight cover helps increase circulation to prevent overheating. Plus, this cover is removable and machine washable—allowing you to care for your mattress for many years.

The AS3 comfort layer features Amersleep’s Bio-Pur® foam—a unique plant-based memory foam that doesn’t trap heat like more memory foams. Bio-Pur® is made with partially plant-based oils, rather than 100 percent petroleum-based oils. This process results in a sleep surface that is non-toxic and safe.

Beneath the Bio-Pur® layer is Amerisleep’s Affinity foam with HIVE® technology. HIVE® is designed to comfort and support each area of the body differently. Vulnerable areas like the neck and back receive more firmness and stability with HIVE®. Near areas that often develop pressure points, like the hips and shoulders, HIVE® offers a plush cushion.

The support base of the AS3 is made up of Amerisleep’s Bio-Core® foam. This solid support base prevents sinking and maintains the structure of the mattress.

Amerisleep offers a generous 100-night sleep trial that lets you test out the mattress risk-free. They also offer a generous 20-year warranty to cover any manufacturing defects.

If you are looking for an adjustable base to pair with your split king mattress, Amerisleep offers two high-quality options. We include more details on their adjustable bed frames further down.

SEE ALSO: Amerisleep Mattress Review

The Zoma Mattress is designed to facilitate faster muscle recovery, so you wake up with less pain and stiffness. This makes Zoma a favorite mattress for athletes and those who live an active lifestyle.

This medium memory foam mattress offers two advanced technologies that target each area of the body. Together, these layers create the perfect balance of cushioning and responsiveness.

The soft cover promotes airflow around the surface of the mattress to help you stay cooler throughout the night. Beneath this cover is a layer of memory foam with Triangulex™ technology. As its name suggests, Triangulex™ features hundreds of triangle cutouts. These cutouts provide deep compression near pressure points and more resistance near the back and neck.

To increase the responsiveness of the mattress and prevent sinking, Zoma has included a layer of their Reactiv™ technology. This material responds quickly, so no matter how often you change position during the night, you will stay supported. The base of the Zoma Mattress features Support+ foam, a sturdy high-density foam to help the mattress keep its shape and ensure its longevity.

With the Zoma Mattress, a 100-night sleep trial offers you the chance to be sure the mattress is right for you. They also include a 10-year warranty.

SEE ALSO: Zoma Mattress Review

Couples often enjoy a split king mattress with an adjustable base, and GhostBed helps you save when upgrading your sleep experience with their Split King Adjustable Set. You can package one of four GhostBed mattresses with the company’s adjustable bed.

The GhostBed Adjustable Base offers:

• Numerous massage modes for soothing aches and pains
• Five preset positions and the opportunity to program your own
• A child lock for peace of mind during the day
• Under-bed lighting
• USB ports

Whether you prefer a hybrid or a memory foam mattress, this bundle is a great way to save on your comfort. GhostBed’s mattresses are backed by a 101-night sleep trial and a 20-year warranty. The base comes with a limited lifetime warranty, which you can extend the terms of for an additional cost at checkout.

SEE ALSO: Best Mattress for Adjustable Beds

The Zoma Hybrid is designed to provide the same restorative benefits of the classic Zoma Mattress, just with some added bounce. The hybrid has four layers wrapped in a soft breathable cover.

The bed’s top memory foam layer has infused gels for a cooler night of sleep. This layer also includes foam cutouts arranges in three support zones. Under your head, shoulders, and legs, cutouts are spaced further apart for added compression and pressure relief. However, along the back, the foam is firmer to support the lumbar spine and reduce over sinking.

A layer of Reactiv™ transitions between the bed’s comfort and support layer.  Reactiv™ is a buoyant foam that adapts to your movements, minimizing sinkage.

The hybrid contains supportive pocketed coils, with a foam base underneath for structure. Manufacturers wrap every coil in a pocketed coil system to reduce motion transfer and decrease noise. No matter how much you toss and turn, your partner should remain undisturbed.

Every Zoma mattress comes with a 100-night sleep trial and a 10-year warranty.

SEE ALSO: Best Mattress for Bed Sores/Pressure Ulcers

The Vaya Mattress is an affordable, high-quality mattress-in-a-box brand. They are a newer company receiving positive customer feedback on Amazon. This mattress contains two hypoallergenic foam layers. Each layer is backed with a CertiPUR-US® certification, ensuring it’s low in VOCs and contains no ozone-depleting substances. If you or your spouse suffer from allergies, asthma, or other respiratory issues, the Vaya Mattress is an excellent option.

The Vaya Mattress is a medium mattress—suitable for most sleep positions and body types. Beneath a lightweight cotton cover is a layer of soft, breathable foam. Vaya foam contours to the body for a weightless sleep and helps promote air circulation. This foam is also more responsive than traditional memory foam, which helps sleepers feel lifted on the mattress. This responsiveness also keeps the hips and shoulders aligned throughout the night. Supporting this soft layer is a support base of high-density foam for durability and structure.

The Vaya Mattress can be placed on many popular bed frames, including solid, slatted, and adjustable bases. Vaya also includes a 100-night sleep trial and a 10-year warranty with each of their mattresses.

If you and your spouse are looking for an organic split king bed, the Avocado Green Mattress is a great choice. This bed includes organic materials that were harvested using only the most sustainable methods.

The Avocado Green Mattress features a GOTS organic cotton cover with a quilted design to improve breathability. The comfort layer contains 3 inches of GOLS certified latex foam—guaranteed to be free of harmful pesticide residues. This layer contours to the joints similar to memory foam. But, unlike memory foam, latex foam has a slight bounce—making it ideal for heavier sleepers who don’t want to feel “stuck” in the mattress.

The base of the Avocado Green contains 1,414 individually wrapped spring coils. Each coil in this support system is tuned to offer a balance of firmness and compression. Edge support around the perimeter of the Avocado Green also helps increase durability and structure.

Avocado offers a 1-year sleep trial and a 25-year warranty with each of their mattresses.

What Is a Split King?

A standard king size mattress measures 76 inches by 80 inches. Because a twin XL mattress measures 38 inches by 80 inches, it is easy to place two twin XL mattresses side by side to create a full size king bed.

Some mattress brands may not include a split king in their lineup of sizes. But if they offer a twin XL option, you can simply purchase two of these and place them together to form your split king. See our twin XL vs split king guide for more information and recommendations.

Here’s a quick overview of other mattress sizes to consider.

Why Would I Need a Split King?

Different Firmness Needs

As we mentioned above, the right firmness for one person may not be right for another. Couples often have to compromise when it comes time to purchase a new bed. But with a split king, there is no compromise necessary. This option allows you both to get the perfect firmness for your body type and sleep habits.

Split King Adjustable Base

One of the best ways to improve your sleep is to upgrade to an adjustable base and mattress combo. These high-tech bed frames allow you to change the elevation of your head and legs to create a safer, more comfortable sleep position.

Some of the health benefits that come with an adjustable bed include improved circulation, less snoring, better digestion, and reduced acid reflux. Plus, an adjustable bed base offers better lumbar support and can relieve back pain. Particularly if you choose an adjustable bed for back pain with massage features.

As you shop for an adjustable base, you will notice that many of them offer a split king option. When a base is split, the two sides of the bed can be raised or lowered independently. This feature gives both you and your spouse the ability to adjust your side of the bed.

Best Adjustable Beds

Hospitals have relied on adjustable beds for years. These beds ease symptoms associated with different medical issues, such as adjustable beds for seniors that make it easier to live with arthritis.

Plus, adjustable beds can facilitate a faster recovery. If you are in the market for a new adjustable base for a condition we recommend one of Amerisleep’s advanced bed frames (Read more about best mattresses for seniors here).

Amerisleep Adjustable Bed+

Amerisleep’s Adjustable Bed+ is a state-of-the-art bed frame with head and leg articulation, plus a host of other high-tech features. Pairing your new Amerisleep mattress with this adjustable base brings you a luxurious sleep.

When purchasing the Adjustable Bed+, you can bundle the frame with your preferred Amerisleep mattress. With this package, Amerisleep offers a $450 discount on the mattress.

This base has a “Flat” button and a “Snore” button on the wireless remote control. The “Flat” selection gently returns the bed to a flat position to make climbing in and out of bed easy.

The “Snore” button triggers a slight head elevation to open the airways and reduces snoring and symptoms of sleep apnea. You can use this button to reduce your spouse’s snoring without having to wake them up.

This base is also equipped with wall-glide technology to prevent the base from sliding away from the wall when raised. This feature allows you to comfortably reach objects on your nightstand with ease—even when the bed is in the fully upright position.

To help you drift off to sleep peacefully, Amerisleep has included a dual full-body massage function with three different speeds. This base also has a convenient under-bed lighting feature, USB ports, and programmable positions. You can also connect the base to your smartphone or give voice commands through your Google Home or Amazon Alexa.

The Amerisleep Adjustable Bed+ comes with a 10-year warranty. This generous warranty will ensure that your investment is protected throughout many years of use. Amerisleep will also deliver and set up the base for free

Amerisleep Adjustable Bed

Amerisleep also offers a slightly modified version of the Adjustable Bed+. This frame has the same head and leg articulation and many of the advanced features listed above but at a lower price.

The Amerisleep Adjustable Bed comes with a remote control and the option to connect to your smartphone via Bluetooth. Plus, it features an anti-snore button, a Zero Gravity position, and programmable sleep positions. The quiet motor will ensure you don’t wake your spouse when adjusting the bed during the night.

Unlike the Bed+, this frame does not include the massage feature, under-bed lightning, or wall-glide technology. But if you are shopping on a tight budget, this bed offers you a healthy and comfortable sleep position at an affordable price.

Amerisleep’s Adjustable Bed can be placed on the floor or any flat surface and pairs well with most bed frames. Amerisleep offers a 10-year warranty with this base to ensure it keeps supporting you for many years.

What Type of Mattress Can Be Used on an Adjustable Frame?

Most types of mattresses can be used on an adjustable base—including memory foam, latex foam, and hybrid mattresses. However, we caution pairing traditional innerspring mattresses with adjustable bases, as the springs may bend out of shape. The setup of a traditional innerspring mattress is different from a hybrid mattress, which has a pocketed coil design that adapts well with the base’s movements.

Certain air mattresses also can’t be used on an adjustable frame. These beds have a customizable air pressure system built into the mattress, allowing you to change the firmness level of the bed. But bending these mattresses on a split king adjustable bed can restrict airflow and cause damage to the mattress.

Adjustable frames also come in a variety of mattress sizes—including twin, twin XL, full, queen, and king. However, it is important to note that split adjustable beds are typically only offered in a standard king size. California king size adjustable frames are not often readily available in a split option, but they are available as a non-split adjustable base.

Most split queen adjustable bases are not attached—these bases are typically two single 30 by 80 inch bases placed side by side. However, because 30 by 80 inch mattresses are not standard, split queen adjustable beds are difficult to find.

Other Things to Consider

When shopping for your new split king mattress, there are a few things you will want to keep in mind. Bringing a new mattress home is an important decision, and you want to make the most informed choice possible. To help you select a bed suited to your needs, we breakdown the most common mattress types and firmness levels below.

Mattress Types

A mattress’s “type” is determined by the materials used within each layer. These materials can impact the comfort, quality, and support of the bed. Therefore, it is helpful to know what type of experience you will find with each different type.

Foam Mattresses

• Memory Foam: Memory foam mattresses are incredibly soft, responsive beds that hugs the curves of the body without pressure build-up. This material provides a weightless sleep so your body can repair and rebuild. Because traditional memory foam tends to trap heat, it is best to opt for a plant-based foam mattress. Plant-based foams have less heat retention and a faster response time than most memory foams. Also, because this foam is made with less petroleum-based oils, it is also safer and less toxic.
• Latex Foam: Latex is a highly durable and naturally sustainable material that has become a popular mattress material. This foam has more elastic properties than memory foam, so while it does contour, it has a bounce that keeps you lifted rather than cradled. If you prefer the comfort of foam but also want more bounce, you may find a latex foam mattress more comfortable.

Hybrid Mattress

As its name suggests, a hybrid mattress is a combination of foam and innerspring coils. These beds typically feature a 2 to 3 inch foam comfort layer—made of either memory or latex foam. Supporting this layer is a base of individually wrapped spring coils.

In some hybrid mattresses, coils are tuned to provide the ideal comfort level for each area of the body—so they are softer near the hips and shoulders and firmer near the head, back, and neck.

Innerspring Mattress

Innerspring mattresses have been popular for many years—this is mainly due to their low price point. However, these beds are quickly falling out of favor as people switch to more advanced foam and hybrid mattresses.

Innerspring beds have a support base of spring coils, but they do not have the plush comfort layer of foam that contours to the body. Some innerspring beds feature foam in their comfort layer, but it is usually less than 1 inch. Plus, spring coils can become damaged quickly and may stick up—resulting in painful pressure points.

Firmness and Sleeping Positions

You may not give much thought to the position you sleep in each night, but your sleep habits can affect what type of bed you find most comfortable.

Depending on your position in bed, certain parts of your body will sink more than others. It’s important that sinking is controlled so the spine stays in alignment with the rest of your body. If the spine is out of alignment, it can cause pain and stiffness in the morning.

Below are the most common sleep positions and the firmness level most suitable for each.

• Side Sleeping: A medium-soft to medium mattress will cushion the heaviest parts of the body (the hips and shoulders), while also preventing excessive sinking, so the spine stays straight.
• Back Sleeping: A medium to medium-firm mattress will keep body weight evenly distributed and prevent the hips from sinking and throwing the spine out of alignment.
• Stomach Sleeping: A medium-firm to firm mattress will prevent the hips from sinking and putting a strain on the upper back and neck.
• Combination Sleeping: A medium mattress will provide enough cushioning for resting on your side, and also enough firmness to prevent the hips from sinking when back or stomach sleeping.

Frequently Asked Questions

Is a split king the same as two twin XLs?

Yes. The dimensions of two twin XLs placed side by side equal those of a king size mattress. Couples with different sleep styles and those with split king adjustable beds love split king mattresses for the extra sleep-promoting benefits they provide.

How much does a split king mattress cost?

Split kings cost more than standard kings or even California kings because they are two separate mattresses, so they require a bit more material to make, resulting in an increased price. On average, a split king size mattress will cost between $2,000 and $3,000 because you’re buying two separate twin XL beds instead of one mattress.

Is a split king adjustable bed worth it?

We believe adjustable beds are always worth the investment as long as you’re choosing one that’s a good value. Some adjustable beds have very expensive prices but don’t contain all that many bells and whistles. When searching for a good adjustable bed, look at the price, and then look at what it comes with. If you think you’re being price gauged, try shopping with another brand. Trust us, there are plenty of great adjustable beds out there and they don’t cost an arm and a leg.

What is the best split king mattress?

It depends on who you ask! Everybody has different sleep needs, so your best friend’s favorite mattress probably differs from your mom or dad’s favorite mattress, so on and so forth. To find your best mattress, think about how you sleep, how soft or firm you prefer your bed to be, and body type. With those three things in mind, you can find a comfortable bed in no time.

Do adjustable beds ruin mattresses?

As long as the mattress in question is compatible with an adjustable bed, it should be just fine to pair with an adjustable bed frame. Adjustable beds rarely ever damage all-foam mattresses, and most hybrids pair well with them, too. The only beds to really question are innersprings—beds with coils are hit or miss with adjustable bases. Before pairing an innerspring mattress with an adjustable base, reach out to the retailer and ask if the mattress you’re considering is compatible with an adjustable bed.

Conclusion

The great thing about a split king is that you and your spouse don’t have to compromise on comfort when it comes to a mattress for couples. Sleep is valuable, and we want to make the most out of every minute of rest. Unfortunately, it can be hard to do that when we are sleeping on a mattress that is wrong for our body type and sleep position.

If you and your spouse are looking for a good night’s sleep, a split king is the perfect solution. Better yet, you can pair your new split king with an adjustable bed frame and experience even more restorative sleep.