Anyone who’s shared a bed knows that sleep styles can vary considerably. Featuring a design that’s essentially two twin XL mattresses placed side by side, a split king mattress can be a solution for couples with different body types and sleep preferences.
Many split king models are compatible with adjustable bases that let users control the angle of their sleeping surface. Others let co-sleepers each choose the firmness and feel of their side of the bed.
Given its unique design, a split king mattress comes with special considerations. We’ll cover topics like adjustable bases, sheet sizes, and the importance of solid edge support. We’ll also compare traditional king beds with split king mattresses and give in-depth reviews of the best split king mattresses available today.
We’ll cover everything you need to know so you can select the best split king mattress for your needs. Our sleep specialists have researched and tested a variety of mattress models, focusing on features that have the greatest effects for firm mattress comfort levels, such as edge support, temperature control, and motion isolation.
Sleep Doctor’s Picks
Best Overall Mattress
Nolah Evolution 15
The Sleep Doctor’s Review
The Nolah Evolution 15 checked many boxes during our tests. Three firmness levels and a balanced hybrid construction ensured a comfortable model for most of our testing team. Cooling infusions, ArcticTex cover, and breathable coils also made the mattress popular with our hot-sleeping testers.
Buy From Nolah
Hot Sleepers
Medium (5), Medium Firm (6), Firm (8)
Plush, Supportive Surface
Good Value
Pros
- Padded Euro-top helps relieve pressure buildup
- Cooling cover features proprietary ArcticTex fabric
- Tri-zoned coil system for extra lumbar support
Cons
- Couples may find the mid-range and firm models transfer too much movement
- The foam layers may produce off-gassing odor after unboxing
Nolah’s Evolution 15 is designed to maximize pressure relief without trapping too much heat. The hybrid is notable for its plush Euro-top that gently massages pressure points. Co-sleepers can choose from three firmness levels, which Nolah calls Plush, Luxury Firm, and Firm. Our testing team found that these options correspond to medium (5), medium firm (6), and firm (8) on our 10-point firmness scale.
Why We Like It
We found that the Plush option performs especially well for side sleepers under 230 pounds, while heavier side sleepers preferred the Luxury Firm model. The thick comfort system delivers plenty of cushioning to the hips and shoulders, which are vulnerable pressure points for side sleepers.
Back sleepers on our testing team between 130 and 230 pounds were evenly split among proponents of the Luxury Firm and Firm options. But those over 230 pounds clearly preferred the greater support of the Firm mattress, while those under 130 pounds liked the added contouring of the Luxury Firm. Many stomach sleepers also said they could go either way, but those with bigger bodies mostly opted for the firmer of the two.
Thanks to a number of cooling features, we found that the mattress regulates temperature well. While the comfort system is fairly thick, the foam layers are more breathable than conventional foam. The pocketed coils promote airflow, and their added bounce keeps sleepers from sinking too far into the mattress.
The Nolah Evolution 15 comes in all the standard mattress sizes, as well as a split king option that lets co-sleepers choose between the three firmness levels for each side of the mattress.
We found that the Nolah Evolution 15 delivers notable pressure relief for most sleep styles and body types. The mattress also has above-average temperature control thanks to breathable foams and pocketed coils.
How Does It Feel?
Using proprietary ArcticTex fibers, the quilted cover is engineered to dispel heat. The Euro-top contains breathable polyfoam, which also helps the surface stay cooler. Two additional layers of polyfoam support spinal alignment by evenly distributing body weight, while graphite infusions are designed to minimize heat retention.
A pocketed coil system limits motion transfer while encouraging air circulation. The coils are zoned so that the torso area receives extra reinforcement. Sturdier coils along the perimeter boost edge support, which minimizes gapping in the center of a split king mattress. A base layer made from recycled plant fibers stabilizes the entire mattress.
The sides are encased in embroidered fabric and feature convenient carrying handles. The seven layers total 15 inches, so fitted sheets with extra deep pockets may be needed.
Best Value Mattress
Nectar Mattress
The Sleep Doctor’s Review
A competitive price-point, year-long sleep trial, and lifetime warranty make the Nectar Mattress an appealing option for value seekers. The all-foam model also has a firmer-than-average feel that appealed to members of our team that typically don’t go for memory foam mattresses.
Buy From Nectar
Side Sleepers
Medium Firm (6)
Close-Conforming Foam
Great Value
Pros
- Soft and breathable polyester-blend cover
- Thick memory foam cradles the body
- Includes a 365-night sleep trial and a limited lifetime warranty
Cons
- People who weigh more than 230 pounds may find they sink too deeply into the foam layers
- Couples who prefer a responsive surface for sex may find the mattress too plush
The Nectar is an affordable all-foam model that cradles the body to alleviate tension. Its balanced medium firm feel registers as a 6 on our 10-point firmness scale and supports a range of sleep styles.
Why We Like It
The Nectar’s pliable all-foam design makes it well suited for couples with adjustable bases who like having the option of raising or lowering the head of the bed on each side independently. Along with split king, the Nectar is available in the six standard mattress sizes.
We found the Nectar to be a great budget-friendly option for side sleepers and people under 230 pounds. It also sleeps relatively cool for an all-foam mattress and features top-notch motion isolation and pressure relief.
How Does It Feel?
Made from a blend of polyester and nylon, the soft cover helps wick away heat and moisture. Plush memory foam cushions areas prone to pressure points on the hips, shoulders, and spine. Close contouring foams tend to trap heat, but the Nectar uses gel infusions designed to increase breathability.
A layer of adaptive polyfoam helps spread body weight evenly across the mattress. The support core uses 7 inches of high-density polyfoam to reinforce the upper layers. A slip-resistant base cover helps keep the mattress firmly rooted. The foam layers amount to 12 inches, which is an average mattress height.
Side sleepers often benefit from a foam mattress’ closer contouring. Unsurprisingly, we found that the Nectar delivers ample pressure relief to side sleepers in any weight group. The plush memory foam cradles the hips and shoulders while encouraging good sleep posture. Most stomach and back sleepers should feel supported by the dense polyfoam core, but sleepers over 230 pounds may experience some sinkage and find it more difficult to change positions.
Best Luxury Mattress
Saatva Solaire
The Sleep Doctor’s Review
The Solaire by Saatva is a luxury airbed that is adjustable between soft and firm feels. This design allowed each of our testers to find a level that fit their support needs. You can also choose different firmnesses for each side of the bed, which should appeal to couples.
Buy From Saatva
Couples
50 Firmness Settings
Customizable
Fair Value
Pros
- Adjustable firmness settings with 50 nuanced feels
- Excellent temperature control
- Free White Glove delivery
Cons
- Like other airbeds, the Solaire holds a higher price-point
- Some couples may find the surface’s responsiveness transfers more movement
As an adjustable airbed, the Saatva Solaire gives couples maximum customization. The queen size and larger models have 50 firmness settings on each side of the bed so sleepers can experiment with various levels of support.
Why We Like It
With a range of nuanced settings, we found that the Solaire delivers balanced support and pressure relief for the full gamut of sleep positions and body types. Our tests also revealed excellent temperature control and above-average ease of movement and durability.
While the Solaire doesn’t come in twin size, it’s available in the other standard sizes as well as split king and split California king. Customers can test the bed for 365 nights, which is longer than the average sleep trial.
While the Solaire may be cost-prohibitive for some shoppers, a durable design, professional installation, and a lengthy sleep trial help justify its higher price-point for couples seeking a luxury airbed with a wide range of personal customization.
How Does It Feel?
A 3-inch quilted Euro-top boosts pressure relief without trapping too much heat. The layer is sturdier in the center so that the back and hips receive extra support. An organic cotton cover is designed to draw heat away from the mattress’ surface. The cover incorporates Guardin, Saatva’s exclusive antimicrobial treatment.
Zoned Talalay latex conforms to the body while still supporting the heavier torso area. A layer of gel-infused memory foam offers deeper contouring without generating too much heat. The comfort system is finished with a protective barrier that safeguards the mechanical core from moisture.
The support core features vulcanized rubber air chambers that inflate or deflate via remote control. Foam lining stabilizes the core and dampens any noise from the chambers. The 50 settings span from soft (3) to firm (8), so users can finely calibrate their comfort level.
Best Mattress for Back Pain
PlushBeds Botanical Bliss
The Sleep Doctor’s Review
Latex mattresses are often great choices for back pain, offering cradling for the spine while supporting the body. Our testers with persistent back pain enjoyed the PlushBeds Botanical Bliss’ supportive contouring, as well as the two firmness and three profile options.
Buy From Plushbeds
Back Pain
Medium Firm (6), Firm (7)
Responsive Latex
Good Value
Pros
- All-latex construction ensures excellent durability and responsiveness
- Multiple firmness and thickness options
- Cotton and latex hold organic certifications
Cons
- Sleepers with sharp joint pain may want a more adaptive mattress
- Stomach sleepers who weigh less than 130 pounds
If you live with frequent or chronic back pain, you should use a mattress that promotes even alignment and provides adequate support for your body. Each layer of the PlushBeds Botanical Bliss is composed of organic latex, a naturally durable and responsive material that gently cushions the body. Latex is ideal for people who dislike the “hug” of memory foam, or find that they sink too much on all-foam mattresses.
Why We Like It
During our tests, we found the Botanical Bliss sleeps quite cool. The latex is ventilated to promote airflow throughout the interior and the cotton is exceptionally breathable. We also awarded positive ratings for ease of movement. The natural, gentle bounce of latex allowed us to move across the Botanical Bliss’ surface without sinking or feeling restricted.
The PlushBeds Botanical Bliss is a long-lasting, eco-friendly latex mattress that offers decent cushioning without the body-hug or sink of foam. Excellent cooling also makes the Botanical Bliss a good pick for hot sleepers.
How Does It Feel?
You can choose between two firmness levels for your Botanical Bliss, medium firm (6) and firm (7). The latter feels slightly more supportive and the former provides closer contouring, but both feel fairly balanced. If you and your partner have different preferences, you can opt for a split king with medium firm on one side and firm on the other.
The Botanical Bliss is also available in three profiles. The 9-inch model consists of bouncy Talalay latex over two base layers of dense Dunlop latex. This profile is best suited to people who weigh up to 230 pounds. If you weigh more, then the 10-inch or 12-inch model should provide sufficient support. The 12-inch design includes a third Dunlop latex layer for maximum reinforcement.
All Botanical Bliss models are encased in organic cotton covers. This fabric has earned certification from the Global Organic Textile Standard, ensuring sustainable cultivation and processing. Likewise, the latex holds certification with the Global Organic Latex Standard for eco-friendly sourcing of rubber tree plants used to produce the material. These credentials should appeal to anyone who prefers to buy and use products with minimal environmental impact.
Best Mattress for Couples
Bear Elite Hybrid
The Sleep Doctor’s Review
The Bear Elite Hybrid’s balanced feel and variety of firmness options make it a great choice for couples with distinct firmness preferences. Other features couples will enjoy include the foam comfort system’s motion isolation properties, which should reduce nightly disturbances from your partner changing positions at night.
Buy From Bear
Restless Sleepers
Medium (5), Medium Firm (6), Firm (8)
Close-Conforming Foam
Good Value
Pros
- Breathable cover made with Celliant fibers and phase change material
- Three firmness options
- Zoned comfort system for extra lumbar support
Cons
- Couples who prefer a more responsive surface for sex may find the foam layers too plush
- The foams may emit off-gassing odor for the first few nights
Bear designs mattresses with athletes in mind, but a variety of sleepers can benefit from solid pressure relief and support. The Elite Hybrid features thick comfort layers and a sturdy coiled core to ease pressure points and align the spine. With more firmness options than other Bear models, the mattress accommodates couples with distinct preferences.
Why We Like It
Given the different firmness options, we found that the Elite Hybrid can comfortably sleep all positions. The coiled core allows sleepers to change positions with greater ease, but we didn’t notice significant motion transfer. We also found that the mattress regulates temperature well, despite its close-conforming memory foam.
While Bear doesn’t let shoppers select two different firmness options on a single split king purchase, co-sleepers with differing firmness preferences can order two twin XL mattresses since the combined dimensions are identical to the split king size.
With three firmness options to choose from, people of most body types and preferred sleep positions should enjoy considerable pressure relief and support on the Elite Hybrid. Hot sleepers can also benefit from the mattress’ various cooling features.
How Does It Feel?
A plush, hand-quilted cover blends phase change material with cooling Celliant fibers. Cushy memory foam contours the body, while copper infusions are engineered to reduce heat buildup. A layer of zoned polyfoam delivers proportional support so heavier areas like the torso and hips receive more pushback. Cutouts in the foam are designed to promote air circulation.
The pocketed coil core boosts lumbar support and stabilizes the comfort system. Sturdier coils are used along the perimeter to enhance edge support, and a base of high-density polyfoam adds further stability.
All sizes are available in three firmness levels: medium (5), medium firm (6), and firm (8). At 14 inches thick, the mattress is considered high-profile.
Best Cooling Mattress
Tempur-Pedic TEMPUR-breeze
The Sleep Doctor’s Review
All-foam mattresses are often notorious for trapping heat, but the Tempur-Pedic TEMPUR-breeze is a notable exception. A cover using proprietary cooling technology, phase change material, and ventilated foams kept the mattress quite cool during our temperature regulation tests. Our heat guns detected minimal heat retention on the surface.
Buy From Tempur-Pedic
Hot Sleepers
Soft (3), Medium (5), Firm (7)
Close-Conforming Foam
Fair Value
Pros
- Ventilated memory foam for enhanced breathability
- Available in foam and hybrid versions
- Free White Glove delivery
Cons
- Some stomach sleepers may find their midsections sink too deeply into the mattress
- Couples may find the all-foam design restricts movement across the surface
Sharing a bed often generates more heat, so a mattress with cooling features is an asset for couples. The TEMPUR-breeze line from Tempur-Pedic is designed to sleep noticeably cooler than the average mattress with foam comfort layers. The line includes two versions: the PRObreeze, which comes in foam or hybrid options, and the all-foam LUXEbreeze. The PRObreeze has a medium (5) feel, while the LUXEbreeze is available in soft (3) or firm (7) options. All versions feature a cooling cover made with phase change material.
Why We Like It
We found that the entire TEMPUR-breeze line regulates temperature well, making it suitable for people who sleep hot. All models have above-average pressure relief and durability. Edge support is more of a mixed bag, with the hybrid PROBreeze and firm LUXEbreeze outperforming the all-foam PROBreeze and the soft LUXEbreeze.
Shoppers should note that the LUXEbreeze is notably more expensive than the PRObreeze because it uses ventilated memory foam.
How Does It Feel?
Tempur-Pedic is known for its proprietary memory foam, which is engineered to optimize pressure relief without trapping heat. The PRObreeze uses the brand’s traditional TEMPUR foam, while the LUXEbreeze features ventilated memory foam for extra breathability. A pocketed coil core gives the hybrid added bounce, while the all-foam models use polyfoam support cores.
Both models regulate temperature well, but the PRObreeze is slightly more breathable because of its coiled core. Our tests showed that the foam models are more durable than the average all-foam mattress. However, edge support is less robust on the all-foam PRObreeze and the soft version of the LUXEbreeze.
Tempur-Pedic doesn’t let customers mix and match models or firmness levels when purchasing a split king mattress. The LUXEbreeze and PRObreeze have different profiles, so shoppers should note they are unable to form a split king by purchasing one twin XL size of each model. However, sleep partners with different comfort preferences can order two twin long mattresses. This size is the same as twin XL, making the combined size the same as a king or split king when the twin long mattresses are pushed together.
Why You Should Trust Us
Buying a mattress can be stressful, even for the most seasoned shopper. Marketing hype and seemingly endless options can make it difficult to focus on features that really matter.
We’ve tested hundreds of mattresses over the years, so we know which performance factors impact sleep quality the most. Our testers have different body types, sleep positions, and personal preferences, which allows us to predict which models will be most compatible with various sleep styles.
Each mattress is rated according to criteria like temperature control, pressure relief, and durability. For split king models, we put extra emphasis on metrics like edge support, motion isolation, and firmness options. We realize a mattress can be a big investment, so we include models to fit varying budgets.
What is a Split King Mattress?
A split king mattress is separated into two distinct twin XL size mattresses, each measuring approximately 38 inches wide by 80 inches long. A divided mattress allows partners to move without creating motion disturbances, and some companies let shoppers pick a different firmness level for each side of the bed.
What Size is a Split King Mattress?
A split king mattress is divided down the middle, creating two 38-by-80-inch sleeping surfaces. Put another way, a split king is the equivalent of two twin XL mattresses placed side by side.
The combined mattresses correlate to a standard 76-by-80-inch king size mattress. Most couples find that moving two smaller mattresses is much easier than maneuvering a hefty king size bed.
Are Split King Mattresses Comfortable?
A split king mattress can be a real advantage for couples with very different sleep preferences. With a traditional king size mattress, co-sleepers have to negotiate mattress type and firmness level. A compromise often leads to substandard comfort and support for at least one partner. Split king beds can address differences in body weight and sleep position by granting personal customization.
Customize for Individual Sleep Preferences
A split king mattress gives couples more freedom to personalize their sleep surface. While not all companies let shoppers customize the firmness level of each side of a split king mattress, most offer mattresses in a twin XL size so that co-sleepers can purchase two twin XL mattresses to suit their individual needs. Couples can increase customization by combining a split king mattress with an adjustable base.
Firmess
Mattress firmness is key when it comes to optimal support. A firmness level appropriate to body weight and sleep position promotes healthy spine alignment. For example, a side sleeper under 130 pounds typically needs a softer mattress that cradles the shoulders and hips. On the other hand, a back or stomach sleeper over 230 pounds generally requires a firm surface to minimize sagging.
People with chronic muscle or joint pain may require a different firmness level than their partner. By customizing firmness and support, a split king mattress can address individual health conditions.
Mattress Type and Comfort
Some mattress types are better suited to certain sleep styles and body weights than others. Back and stomach sleepers often benefit from a hybrid’s balance of contouring and support. Side sleepers, on the other hand, often prefer all-foam models that more closely conform to the body.
How a comfort system is constructed has a huge impact on perceived comfort and support. While some sleepers prefer a plush pillow-top design, others enjoy a more solid surface. A split king mattress lets co-sleepers choose the best mattress to meet their individual needs.
Motion Isolation
Motion isolation describes how well a mattress prevents movement from traveling from one side of a bed to the other. Co-sleepers are more likely to be disturbed by their partner’s movements when motion isolation is weak. All-foam mattresses are usually better at isolating motion than coil-based models.
A split king mattress automatically creates a motion barrier with its divided design. This gives co-sleepers more freedom to choose a mattress without worrying about bouncier models disturbing their partner.
Split King Adjustable Bases
Couples can take customization even further when pairing a split king mattress with an adjustable base. The design lets sleep partners modify the angle of their individual mattress, which can be helpful for health conditions like snoring and acid reflux.
Adjustable bases also accommodate dissimilar nighttime routines. The ability to operate each side of the bed independently lets a person sit and read in bed without worrying about disturbing their partner who goes to sleep earlier. Some designs also include luxury features like massage and temperature settings.
Things to Consider When Choosing a Split King Mattress
Like any mattress model, a split king bed comes with advantages and disadvantages. Extra cost, special sheets, and adequate edge support are important considerations when buying a split king mattress.
How to Keep Split King Mattresses Together
One potential drawback of a split king mattress is the gap separating the two mattresses. There are a few workarounds for closing troublesome gaps. For couples using a split foundation, sometimes all it takes is readjusting the connector. Most split frames have adjustable metal connectors that calibrate the distance between the two mattresses.
If a gap still persists, couples can try support braces that are designed to keep individual bases connected. Alternatively, a traditional king size mattress topper can cover an unwanted gap.
You May Need Different Sheets
Sleeping on a split king bed often requires purchasing more than one type of sheet set. A split king mattress uses two twin XL fitted sheets and a king size top sheet. Couples can also opt for a single king size fitted sheet, though this can be difficult to spread across both mattresses.
Some manufacturers make split king sheet sets, but these are harder to come by. Keep in mind that split adjustable beds require split fitted sheets.
Look for Mattresses With Good Edge Support
A mattress with robust edges will offer more even support. Many manufacturers use thicker coils or high-density polyfoam to reinforce a mattress’ perimeter.
When edge support is weak, a split king bed is more prone to buckling at the intersection of the two mattresses. Sagging can magnify any center gap, so strong edge support should be a priority when choosing a split king mattress.
Split King Mattresses Cost More Than a Traditional King
It’s always a good idea to consider your budget when shopping for a new mattress. Since a split king includes two mattresses, it’s usually more expensive than a traditional king size bed. While budget split king and king models may vary only slightly in price, luxury split kings can cost several thousand dollars more than their traditional king counterparts.
Another cost factor to note is that split king sheets are usually pricier than standard king size sets.
Pros and Cons of Split King and Traditional King Mattresses
A split king bed is generally more expensive than a traditional king size mattress, so shoppers should carefully consider their pros and cons. While the split king design offers sleep partners more personal latitude, co-sleepers still have to negotiate bed frames, toppers, and sheets.
Split King Mattress vs. King Mattress
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Split King |
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Traditional King |
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About The Author
Certified Sleep Science Coach, Director of Product Testing
David is a Certified Sleep Science Coach with a lifelong passion for well-being and health optimization. His interest in sleep developed with the arrival of his son, when sleep suddenly became a precious commodity.
- POSITION: Side sleeper
- TEMPERATURE: Hot Sleeper
- CHRONOTYPE: Lion
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