We may receive financial compensation for products purchased through links on this website. Why Trust Best Mattress Brand Caret Down Our proficient team of sleep science coaches, engineers, and product evaluators rigorously inspect hundreds of mattresses using our unique product methodology. Each article is scrutinized for precision, citing only credible sources. Systematically reviewing our content and recommendations, we align with the latest scientific literature and expert insights. Our top-rated mattresses have been personally evaluated and highly rated. You spend around a third of your day in bed, so investing in the right mattress is a smart move. And if you and your partner enjoy luxury and plenty of space, a king mattress is a must. We’ve rounded up our picks for the best king mattresses you can buy online in 2023.Best King MattressesBrandModelHighlightsPrice (Queen)Amerisleep AS3Features pressure-relieving Bio-Pur® and HIVE® technology to promote healthier sleep$1699Amerisleep AS5 HybridContains plant-based Bio-Pur® and Active Flex for contouring and support$2299Zoma MattressContains cooling gels and dynamic support technologies$899Zoma HybridContains responsive foams with targeted support and springy pocketed coils$1099Vaya MattressBudget-friendly king size option fit for all sleepers$799Purple HybridContains proprietary Purple Grid™ to offer "No-Pressure" support$1899Nest Bedding Alexander Signature HybridAvailable in multiple firmness options to suit different sleep needs$1799When searching for a quality king size mattress, keep in mind, mattresses are made differently to tailor to different sleep needs. Without considering what you need from a bed, it can be hard to pinpoint the best king mattress. While comparing your king mattress options, think about how you prefer to sleep, whether you like a soft or firm bed, and keep an eye out for sleep-promoting technologies that interest you.With these things in mind, you’ll be able to find the best king mattress in no time. Best King Size Mattress Overall: Amerisleep AS3 When searching for the best king mattresses, the Amerisleep AS3 is a popular choice. The AS3 is Amerisleep’s medium mattress and offers a good balance of comfort and support. It’s a versatile choice for most, especially for couples that have different sleeping styles. Warranty 20 Years Sleep Trial 100 Nights Shipping FreeBest mattress featuresBio-Pur® foam’s plant-based design increases the material’s breathability and gives it a faster response time.HIVE® technology adds flexible cushion to the shoulders and hips areas.Bio-Core® foam resists sagging and indentation, ensuring a king size mattress remains supportive.Recommended for...Couples with different sleep styles who want to share a king size mattress.People who want to add an eco-friendly king size mattress to their master bedroom.Sleepers interested in relaxing on a king size memory foam mattress after a long day.Save $300 on the Amerisleep AS3 with our discount code. Claim Deal Amerisleep makes and sells a range of mattresses, designed with different types of sleepers in mind. Their range includes soft, medium, medium-firm, and firm mattresses — so there’s a mattress to suit you whether you’re a front, side, or back sleeper. The mattress is also great at isolating motion, so you’re unlikely to be disturbed in the night.Amerisleep’s AS3 mattress is made of multiple layers, reaching 12 inches in depth. First, there’s a 3-inch layer of plant-based memory foam. This Bio-Pur® layer is more breathable than traditional memory foam, so you’ll stay cool throughout the night. You’ll also avoid that “stuck” feeling if you move during the night, as Bio-Pur® regains its shape in seconds.Under the Bio-Pur® is the Affinity layer with HIVE® technology. HIVE® offers targeted support, which means your mattress is firmer where you need it and softer where you want it. Five zones within the mattress are designed to support your body effectively and promote a healthy sleep posture.Finally, the AS3 mattress is finished with a Bio-Core® layer. This layer supports the materials above and provides extra durability. It’s thanks to this high-quality layer that Amerisleep is able to offer an industry-leading, two-decade warranty.Amerisleep offers a 100-night trial, with free shipping and returns. The company also offers an impressive 20-year warranty.The Amerisleep AS3 in king size currently retails for $1699. Best Soft King Size Mattress: Amerisleep AS5 Hybrid Amerisleep’s softest option is the AS5 mattress. The AS5 is available as both a memory foam and a hybrid mattress, and we’ve chosen to focus on the latter for its added bounce. If you’re a side sleeper looking for a mattress that’s luxurious and practical, the AS5 Hybrid is a perfect choice. Warranty 20 Years Sleep Trial 100 Nights Shipping FreeBest mattress featuresPlush Bio-Pur foam follows the curves of your body, eliminating pressure points.Active Flex keeps you from sinking too far into the mattress’s cushion without affecting its soft feel.Pocketed coils support your body and maintain a healthy spine alignment.Recommended for...Side sleepers looking for a soft, conforming king size mattress.Sleepers who want to upgrade a master bedroom with a soft bed.Petite people interested in a pressure-relieving mattress for a bigger bedroom.Save $300 on the Amerisleep AS5 Hybrid with our discount code. Claim Deal The AS5 Hybrid is 14 inches thick, with four layers. On top is 3 inches of Bio-Pur® foam, which we mentioned is cooler and more responsive than traditional memory foam. Plus, it’s environmentally friendly since Amerisleep replaces certain petrochemicals with plant-based alternatives during production.Next is 2 inches of Active Flex, a material that prevents you from sinking too far into the mattress without compromising on its soft feel. Thanks to Active Flex, you don’t need to worry about feeling swallowed by your mattress.A layer of pocketed coils supports the bed. There are up to 900 springs giving the bed its signature bounce while minimizing motion transfer. The pockets surrounding each coil allow them to react individually, rather than enable movement to travel across the mattress.Rigid foams surround the coil’s perimeter, providing edge support. Edge support can make it easier to get in and out of bed. If you’re looking for a mattress for arthritis or another chronic pain condition, edge support can make starting your mornings off right much easier.An inch of foam forms the bed’s base and keeps the coils structured. A soft, breathable cover surrounds the entire mattress.A king size AS5 hybrid costs $2299, and it includes a 100-night sleep trial and a 20-year warranty. Best Memory Foam King Size Mattress: Zoma Mattress The Zoma Mattress boosts muscle recovery and athletic performance. The gel-infused memory foam contours to your body to relieve pain points more effectively. Warranty 10 Years Sleep Trial 100 Nights Shipping FreeBest mattress featuresGel memory foam molds to the body to relieve pressure while staying cool to the touch.Bouncy middle layer of Reativ™ foam prevents a sleeper from sinking too far and feeling trapped.Base layer of Support+ foam remains sturdy and strong after years of nightly use.Recommended for...People in warm climates or who otherwise sleep hot seeking a cooling, king size mattress.Couples who are physically active and want a mattress that promotes restoration while they rest.People looking for targeted support and pressure relief features.Save $150 on the Zoma Mattress with our discount code. Claim Deal The Zoma Mattress was designed with athletes in mind. Thanks to the deep compression from the Triangulex™ layer, you’ll feel better relief on your major joints and muscles.The mattress has been designed to be supportive where you need it, so you get a better night’s sleep. It’s during deep sleep that our body heals, thanks to the release of hormones that stimulate muscle growth and recovery. This helps athletes to be better prepared to face a day of demanding training and work. You don’t have to be an athlete to enjoy this bed, though.This 11-inch memory foam mattress features three layers. The top layer is gel memory foam featuring Triangulex™, a zoned technology unique to Zoma. It’s designed to relieve pain-causing pressure points by offering enhanced support to your midsection and deeper compression under your hips and shoulders.Next, the Zoma Mattress features a Reactiv™ layer. This contouring layer adjusts automatically as you move and change positions. It contours to your body, offering continuous support. This helps with motion transfer, so you’re less likely to find your sleep interrupted as you move.The bottom layer of the mattress adds stability. It also helps with durability, so your mattress feels supportive for longer. This layer also provides consistent pressure relief for key areas like your shoulders and hips.The Zoma Mattress is finished with a breathable fabric cover. This wicks away moisture and heat during the night, so you stay cool.Like many online mattress companies, Zoma offers a 100-night trial. There’s also a 10-year warranty.The Zoma Mattress in king size retails at $799. Best Cooling King Size Mattress: Zoma Hybrid Like the original Zoma Mattress, a Zoma Hybrid was designed to promote body recovery. The mattress’s unique foams and pocketed coils prevent sleep disturbances and spinal misalignment while providing plenty of pressure relief. Warranty 10 Years Sleep Trial 100 Nights Shipping FreeBest mattress featuresGel infusions distribute heat across the mattress’s surface, increasing dispersion.Reactiv™ foam buoys the body, keeping you from feeling stuck as the mattress adapts to movements.Pocketed coil support core reacts to every movement without transferring it across the surface.Recommended for...People of all activity levels seeking a bouncy king size mattress.Hot sleepers seeking a cooling, king size mattress with bounce.Side, back, and combination sleepers interested in a buoyant king size mattress.Save $150 on the Zoma Hybrid with our discount code. Claim Deal You don’t have to be an athlete to benefit from the Zoma Hybrid. This 12-inch mattress contains four layers.First, there’s a 2-inch layer of gel memory foam. The foam has segmented cutouts in the head, shoulders, and leg areas while the midsection contains no cutouts. These cutouts increase the mattress’s contouring for more pressure relief. The cutouts also let air into the mattress, decreasing the bed’s heat retention.Next is 2 inches of Reactiv™ foam, a bouncy material that adapts to your movements and limits sinkage. Reactiv™ foam ensures you’re supported no matter your sleeping position and keeps you from feeling trapped in your mattress.The mattress’s support core is 7 inches of pocketed coils, which reduce motion transfer and prevent squeaky coils from disturbing your rest. The coils rest on a 1-inch foam base and are surrounded by firm foams for protection and edge support.A king size Zoma Hybrid is $1,099 with a 100-night trial and a 10-year warranty. Best Budget King Size Mattress: Vaya Mattress The Vaya Mattress is a great bed for those on a budget, as it costs less than $800 for a king. We like the Vaya Mattress because it features CertiPUR-US® certified foams and is designed to suit side, back, and combination sleeping (sorry stomach sleepers, you may need a firmer bed). Warranty 10 Years Sleep Trial 100 Nights Shipping FreeBest mattress featuresSleepers are cushioned and cradled by the top layer of Vaya Comfort Foam.Ventilated Vaya Comfort Foam and breathable cover promote a cool surface.Vaya Base Foam resists sagging and indentation for a durable king size mattress.Recommended for...Couples with different sleep styles who want to share a mattress.Couples and individuals shopping for a king mattress within limited means.People who want a CertiPUR-US® certified king size mattress.Save $300 on the Vaya Mattress with our discount code. Claim Deal The Vaya Mattress is 12 inches tall and features two layers of foam—3 inches of Vaya Foam and 9 inches of durable base foam. Both layers of foam have an open-cell structure to prevent heat build-up.The comfort layer of Vaya foam is 3 inches thick, perfect for cushioning the shoulders and hips. When you lay on this bed, the Vaya foam contours to your body to alleviate pressure points, but it’s responsive enough to prevent sinkage.The base layer of foam is sturdy enough to keep you lifted in the mattress without the risk of sagging for years to come. Plus, Vaya backs their beds with a 10-year warranty, helping you get the most for your money.The cover of the Vaya Mattress is lightweight and breathable to increase airflow.Every Vaya mattress comes with free shipping and a 100-night sleep trial.SEE ALSO: Most Comfortable Mattress6. Purple HybridThe Purple Hybrid mattress is scientifically engineered to offer total pressure relief and support. It features a layer of patented grid technology that gives you support where you need it and comfort where you want it.This top layer features the Purple Grid™. This flexes underneath the areas that need support most, like your hips and shoulders. It also adapts to your body, so it supports you all night long. This layer promotes airflow, which helps to keep you cool. It also features motion isolation so you don’t get disturbed at night.Sandwiched between two layers of foam is the durable base layer. This features individually wrapped responsive support coils. It helps to offer you the right support as you move, as well as extend the durability of your mattress.The Purple® Mattress is finished with a Premium StretchMax Cover. This is stretchy and breathable.While some mattress brands only offer one option, the Purple mattress can be bought in three different comfort levels. The only difference between them is the depth of the Purple Grid™. The Purple Hybrid features a 2-inch Purple Grid™ while the Hybrid Premier is available in 3 and 4-inch Purple Grid™ options.This mattress comes with a 100-night trial and a 10-year warranty.The Purple Hybrid in king size retails for $1899.7. Nest Bedding Alexander Signature HybridThe Alexander Signature Hybrid is designed with an eye for sustainability. There’s a zipper along the side of the mattress that allows you to replace the comfort layer as it wears out. You simply purchase the new comfort layer from Nest Bedding once it’s needed, cutting down on waste and saving yourself the cost of a new mattress.The mattress comes in medium, plush, and luxury firm feels. And when you choose a king or California king size mattress, you can customize it with an internal split. If you and your partner have different firmness preferences, you’ll still both be able to sleep comfortably.The 14-inch tall bed has five different layers. All are wrapped in a quilted cover made with phase change materials to create a cooling mattress.The first layer is an inch of luxury memory foam, followed by 3 inches of Energex™ foam, engineered for support and temperature control.An inch of support foam lies underneath the Energex™ foam, resting on top of the mattress’s pocketed coil support. The wrappings around each coil help isolate motion, preventing you from disturbing a partner at night. Another inch of support foam acts as the base.An Alexander Signature Hybrid is $1,699 with a 100-night sleep trial and a limited lifetime warranty.SEE ALSO: The Best Place to Buy a Mattress & 7 In-Store MythsHow to Buy the Right Mattress OnlineIf this is your first time buying an online mattress it can be daunting. Some mattresses can be tried out in-store, but many are only available to order direct.Buying a mattress online saves time and gives you greater choice. You’re also free from the pressure of sales tactics from well-meaning salespeople. Another bonus of buying online is you can read mattress reviews and comparisons, like this one.To help you buy the best king-size mattress online, here are our tips on what to look for.SizeBefore you order your mattress, make sure that it fits your bed frame, base, or platform. Measure carefully to check whether you need to order a king or California king. Both have the same surface area, but the king is wider while the California king is longer. The king measures 76 x 80 inches, while the California king measures 72 x 84 inches. If you’re on the taller side, the California king could be the better option.If you’re upgrading, choose the right mattress size for your needs. The king or California king offers you more space than a queen-size, so if you have room, it’s a wise choice.FirmnessThe level of firmness you need will help you to choose the right mattress. This often depends on your body type and sleeping position. Side sleepers tend to favor a soft or medium mattress, while back or stomach sleepers prefer a firmer surface.If you tend to move a lot in the night, look for a mattress that offers edge support to keep you comfortable. For people that suffer from back pain, a mattress or topper that supports your pressure points is essential. Some mattresses come with an extra comfort layer, known as pillow-top mattresses.If you’re not sure which firmness level you prefer, try a few mattresses out in-store. You’ll quickly get a feel for whether you want a soft, medium, or firm mattress. You can then use this to help you buy the best king mattress online.Choosing a firmness can be complicated for shoppers seeking a king bed to share. Many partners have different sleep preferences that can result in different comfort needs. A mattress for couples often has a responsive medium feel to suit as many sleep styles as possible.MaterialsThere are lots of mattress types, including foam beds, hybrids, and innerspring mattresses. Many mattress in a boxes are made with poly-foam or memory foam. Some are hybrid mattresses that feature memory foam and springs.While many foam mattresses look similar, different brands will have their own proprietary technology and materials. This can make it harder to compare the benefits of each. For example, some mattresses feature copper-infused or cooling gel layers to help cool you down. Others may achieve this through a breathable layer or a foam structure that helps with airflow. The end result is similar, but you may find you prefer the idea of one technology over another.If eco-friendly materials are important to you, check out the brand’s credentials. See where they source materials, where their products are made, and how they’re produced.Trials and WarrantiesAs it can take a while to adjust to your new mattress, most companies suggest trying it out for at least two weeks. This means that sleep trial periods are often generous — around 100 or 120 days. These trials give you plenty of time to decide whether it’s your perfect mattress or not. If it isn’t, many companies offer a simple return policy.Buying a new mattress is an investment and you’ll keep it for a long time. Because of this, mattress companies offer a long warranty period. You’ll find a 10-year warranty typical, with some brands offering 20 years.Mattress SalesYearly mattress sales are some of the best times to pick up a new king size mattress. Brands often discount their king beds by several hundred dollars during the following sales:Presidents Day Mattress SalesMemorial Day Mattress Sales4th of July Mattress SalesLabor Day Mattress SalesColumbus Day Mattress SalesBlack Friday Mattress SalesCyber Monday Mattress SalesFrequently Asked QuestionsIs there a bed bigger than a king?Yes, there are mattress sizes bigger than a standard king mattress:A Texas king is 80 inches by 98 inchesA Wyoming king is 84 inches by 84 inchesAn Alberta king is 96 inches by 96 inchesAn Alaska king is 108 inches by 108 inchesThese oversized mattresses usually have to be special ordered from a custom mattress maker.Should I buy a king or queen bed?Queen and king mattresses are both excellent choices for couples and single sleepers. If you have a limited budget or a bedroom that’s around 10 feet by 10 feet, a queen size mattress might be the better choice. But if you want a large mattress to complete a master bedroom and are willing to pay more, a king size mattress can provide a good night’s sleep.Is a California king wider than a king?No, a California king mattress is 4 inches narrower than a king mattress. However, a California king mattress is longer than a standard king. If you’re a taller sleeper over 6 feet tall, you might want to choose a California king bed.Will a king bed fit in a 10 x 10 bedroom?Yes, but the bed won’t leave much room for walkway paths and other furniture. This is why we don’t recommend king mattresses for bedrooms smaller than 12 feet by 12 feet. The largest mattress you should consider for a smaller bedroom is a queen bed.What is the difference between a king and a split king?These two mattresses have the same dimensions, measuring 76 inches by 80 inches. However, a split king mattress is divided into halves lengthwise. This feature can make the bed more comfortable for couples, since each partner can sleep on their chosen firmness.Have You Found the Best King Mattress for You?It always helps to compare different mattresses before you make a decision to buy. We’ve compared some of the top mattresses, but it’s important to buy the one that suits your needs. Think about your sleep routine, how you like to sleep, and what type of mattress you want. With the right knowledge, you can be confident you’re investing in the best mattress for you. About the author Bennett CarringtonIf you’re looking for a mattress recommendation, Bennett Carrington can help. Bennett is Best Mattress Brand’s in-house mattress expert. He’s curated dozens of “best mattress” articles with buying tips for sleepers with a wide range of needs. Whether you’re plagued with back pain or suffering from night sweats, Bennett’s guides can steer you toward the most comfortable mattress for your unique needs. In addition to writing for Best Mattress Brand, Bennett is also a grad student pursuing a degree in English Literature. Find more articles by Bennett Comments Cancel replyLeave a CommentYour email address will not be published. Required fields are marked * Comment Name Email I agree to the Privacy Policy of this website. Δ