Best King Size Mattress (2021): Reviews and Buyer’s Guide

Best King Size Mattress (2021): Reviews and Buyer’s Guide

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Mattress Guides
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A good night’s rest starts with a mattress that’s comfortable and supportive. A king size mattress can take your bedroom from basic to luxurious. King mattresses offer the same comfort and durability of smaller mattresses only on a grander scale.

We’ve picked five of the best king size mattresses on the market. These models have the quality and comfort to improve your sleep better for years to come. We’ve also included a mattress shopping guide to help you through the purchasing process.

Best King Mattresses

as3 best bed in a box mattressAmerisleep AS3Features plant-based memory foam and dynamic support technologies to promote sound sleep
$1329Buy Now
zoma sports mattress for athletesZomaContains cooling gels and Triangulex™ technology to keep you sleeping comfortably
vaya mattressVaya MattressBudget-friendly option suitable for all sleepers
amerisleep as5 best mattress for heavy sleepersAmerisleep AS5 HybridCombines cushioning Bio-Pur® with bouncy pocketed coils for an upgraded night's rest
$1889Buy Now
lull mattressLullResponsive enough to support sleepers over 250 pounds
new purple mattress lineupPurple® HybridFeatures the Purple Grid™ to offer "No-Pressure" support
nest latex bedNest Bedding Natural Hybrid LatexContains all-natural latex and is OEKO-TEX® certified

1. Amerisleep AS3

as3 best bed in a box mattress

Amerisleep’s AS3 continues to be Amerisleep’s best seller and with good reason. This medium-feel model balances cushioning with excellent support. On this mattress, sleepers will find themselves cradled in premium foams and materials that are built to last.

The AS3’s cover is made of a soft and breathable fabric. It covers a Bio-Pur® comfort layer that gently contours to the body, filling the curves of the back or side. Bio-Pur® has an advanced open-cell structure that allows air to circulate through it, giving you a cooler sleep experience.

The second layer provides zoned support with HIVE® technology (Harnessing Intelligent Ventilation & Energy). Hexagonal cutouts in this layer are arranged to provide more support at the head, lower back, and knees and lighter support at the shoulders and hips. This layer promotes better spinal alignment, which can reduce aches and pains. The cutouts also wick away heat.

Finally, there’s the support layer made of Bio-Core®, a high-density foam that redistributes weight evenly across the mattress and adds durability.

Amerisleep provides a 100-day sleep trial and a 20-year warranty that covers indentations over three-quarters of an inch.

AS3 Highlights

  • High-quality foams designed for durability
  • Balance of cushioning and support that relieves pressure and maintains a neutral spine
  • Breathability of Bio-Pur® and HIVE® layers prevent heat build-up

2. Zoma Mattress

zoma sports mattress for athletes

The Zoma Mattress was designed for the needs of the active, athletic lifestyle. Its cover and layers support healing and relieve pressure for those who like to test their body’s limits. This medium-feel mattress is made of CertiPUR-US® certified foams, which means they’re free of harmful chemicals and ozone depleters.

The Zoma mattress is covered in an elastane/polyester cover with a mesh-like feel that allows air to circulate and heat to move away from the sleeper. The comfort layer combines Triangulex™ zoned support with gel memory foam. Triangular cutouts at the head and feet provide cushioning under the shoulders and legs and firmer support for the lower back. The cutouts also create more space for better airflow. Simultaneously, the gel absorbs heat while the memory foam cradles the body for a snug feel.

A Reactiv™ transition layer has a latex-like responsiveness that increases the responsiveness of the gel memory foam layer above it. The Zoma’s seven-inch, high-density support layer provides support while further cushioning the body. The combination of zoned support and cooling foams work well for side sleepers and sleepers who like to sink into the mattress.

The Zoma Mattress comes with a 100-night sleep trial and a 10-year warranty with coverage for indentations over three-quarters of an inch.

Zoma Mattress Highlights

  • Zoned support and breathability of the Triangulex™ layer keep the spine aligned and the body cool
  • Responsiveness of the Reactiv™ layer keeps sleepers comfortable as they move
  • Medium feel allows the sleeper to sink into the mattress for better pressure relief

3. Vaya Mattress

vaya mattressIf you’re shopping on a tighter budget, you can’t go wrong with the affordable Vaya Mattress. Sold by Vaya Sleep, the Vaya costs only $530 for a king. Plus, it’s designed to suit the majority of sleepers.

We like the Vaya Mattress because it’s designed with medium firmness and comfortable enough to suit side, back, and combination sleeping alike. It’s even a fit for sleepers over 230 pounds because it contains responsive foams.

The Vaya Mattress contains pressure-relieving, airy, lightweight Vaya foam in the comfort layer, and a sturdy base foam in the core layer. It’s also backed by a 10-year warranty protecting you from sags and indentations.

The Vaya mattress is sold online-only and comes with a 100-night sleep trial.

Vaya Highlights

  • Offers universal comfort
  • Budget-friendly
  • Breathable and cooling

4. Amerisleep AS5 Hybrid

amerisleep as5 best mattress for heavy sleepers We talked about the Amerisleep brand a bit earlier, but we’d be remiss if we didn’t mention their highly-popular AS5 Hybrid, a relatively new addition to their mattress lineup.

Amerisleep offers hybrid counterparts for their AS2, AS3, and AS5 models, and we love their AS5 model because it offers an unbeatable combination of soft, cushioning comfort and bouncy, responsive support. It’s a great soft mattress for side, back, and combination sleepers, and it’s also a great solution for plus-size sleepers seeking a softer bed.

The AS5 Hybrid contains sleep-promoting Bio-Pur® to alleviate pressure and prevent night sweats. What the AS5 Hybrid has that other Amerisleep mattresses don’t is Active Flex—a latex-like layer for added compression and responsiveness. Active Flex offers extra cushion for the shoulders and hips while keeping you lifted in a healthy position.

Below the two layers of foam is this bed’s zoned pocketed coil system, designed to deliver targeted support and minimize motion transfer. These coils allow for more give under the shoulders and hips to relieve pressure. On the other hand, these coils are firmer under the head, torso, and feet to facilitate better alignment. At the very base of the bed is a thin foam layer for added structural support.

We also like the AS5 Hybrid because it has pretty great edge support, so you won’t have to worry about sliding off the sides of the bed. Amerisleep offers a 100-night sleep trial and a 20-year warranty with their AS5, too.

Amerisleep AS5 Hybrid Highlights

  • Cushioning yet bouncy
  • Comfortable for side, back, and combo sleepers
  • Reinforced edge support and responsive coils promote comfortable sleep for heavy sleepers

5. Lull Mattress

lull mattressIf you need a firmer foam mattress, the medium-firm Lull might be for you. Its impressive responsiveness sets it apart from many foam models. This mattress is CertiPUR-US® certified, which means that the foams have been independently tested and found free of heavy metals and certain harmful chemicals like PBDEs and chemical flame retardants.

The low-profile Lull’s top layer is made of cooling gel-infused memory foam. Gel absorbs heat to prevent overheating. At the same time, the memory foam adapts to the unique curves of the sleeper.

Next, there’s a 1.5-inch transition layer that absorbs motion. This layer also evenly redistributes the sleeper’s weight. The support layer, made of seven inches of high-density poly-foam, gives the mattress shape. This model’s firmness and support make it a good choice for back sleepers and heavier weight sleepers.

Lull provides a 100-night trial period with a 10-year warranty that includes coverage for indentations over one inch.

Lull Mattress Highlights

  • Cooling gel memory foam prevents heat build-up
  • Responsiveness of the transition layer prevents sleepers from feeling stuck
  • Enough support for heavier weight sleepers

6. Purple® Hybrid

new purple mattress lineup

The Purple® Hybrid has Purple’s® Purple Grid™ technology, giving it a unique feel and incredible breathability. Side and combo sleepers who like a cool, responsive mattress will probably love the Purple® Hybrid.

This mattress starts with two inches of Purple®’s hyper-elastic polymer grid called the Smart Comfort Grid™. The grid adapts to the shape of the sleeper while leaving columns of open space for air to pass through. It’s protected from the coil support system by a thin, one-inch poly-foam layer.

The entirety of the mattress’s support is a layer of 7.5-inch pocketed coils. Each individually wrapped coil flexes independently of the surrounding coils, which relieves pressure and improves motion isolation. A firm foam edge surrounds the coils to give the mattress better edge support.

Purple® mattresses come with a 100-day sleep trial, which includes a required 21-day break-in period. Their 10-year warranty includes coverage for indentations over one inch.

 Purple® Hybrid Highlights

  • Pressure relief and breathability of the Smart Comfort Grid™
  • Quick response to movement prevents sleepers from feeling stuck
  • Added pressure relief from pocketed coils

7. Nest Bedding Natural Hybrid Latex Mattress

nest latex bed

If you’re looking for a durable, responsive mattress, you need to look no further than Nest Bedding’s Natural Hybrid Latex Mattress. The natural latex used in the comfort layer is OEKO-TEX® certified, which means it’s been tested by an independent organization and found free of substances that are harmful to human health. Nest Bedding’s non-latex foams are CertiPUR-US® certified, so they, too, are free of harmful substances like ozone depleters, chemicals, and heavy metals.

The Natural Hybrid Latex Mattress starts with an organic cotton and wool stretch knit cover quilted to 1.5 inches of Flex Quilting Foam. This thick cushioning layer covers a three-inch layer of Dunlop latex. The latex contours to the sleeper’s body. Dunlop latex has a denser feel than other types of latex, but it’s incredibly durable and quickly responds to movement.

A 1.5-inch layer of comfort foam further cushions the sleeper and protects the upper foam layers from the six-inch pocketed coils of the support core. These coils flex at high-pressure points and reduce motion transfer. Overall, this eco-friendly mattress provides support that works for back, side, and combo sleepers.

Nest Bedding provides a 100-day sleep trial and a limited lifetime warranty that includes coverage for indentations over one inch.

Nest Bedding Natural Hybrid Latex Mattress Highlights

  • Firm but responsive Dunlop latex contours to the body and relieves pressure
  • Natural latex’s inherent durability makes this mattress an investment that will last
  • Targeted pressure relief from the pocketed coils prevents aches and pains

Mattress Types to Consider

While there are hundreds of mattress models on the market, they all fall into four broad types. We’ll give you a brief intro to each type and the kind of sleeper that usually finds it comfortable.

Memory Foam Mattresses

Memory foam’s ability to conform, mold, and contour with heat and pressure make it an ideal mattress material. Under the heat and pressure of a sleeper’s body, memory foam mattresses fill every curve, stretching to relieve pressure at high-pressure points and supporting the lower back, neck, and knees. Once the pressure and heat are removed, the memory foam slowly returns to its original shape. That allows it to continue conforming as the sleeper moves.

Memory foam can be made in low, medium, and high densities. Low-density memory foams have a quicker response to movement. And, because they have less foam per square foot, they’re also more breathable. Low-density memory foams are inexpensive to make, so they’re often found in inexpensive mattresses. However, their low-density also means they wear out sooner than medium or high-density memory foams.

High-density memory foams put more foam in direct contact with the body. On one hand, that means greater contouring and conforming to the sleeper. On the other hand, that means there’s less space for heat and air to escape, which often, but not always, makes high-density memory foams less breathable.

The density of memory foam is not the same thing as firmness. A high-density foam may be relatively soft, while a low-density foam may be fairly firm. Manufacturers often mix high, medium, and low-density foams in their mattresses to achieve a particular feel.

Of the three sleep positions, it’s the side sleepers who tend to benefit the most from memory foam. Memory foam’s pressure-relieving qualities allow it to cradle and contour to the shoulders, lower back, and hips.

Memory foam that cushions the shoulders while supporting the curve of the lower back can also be comfortable for back sleepers. Combo sleepers often need a responsive memory foam mattress to prevent them from feeling stuck in the imprint of their own body.

Stomach sleepers need to be careful on memory foam because their hips may sink down too far, putting painful pressure on the lower back. They should look for a firm memory foam mattress with good support through the hips and lower back to prevent sinkage.

Memory foam does have some downsides. First, it traps heat. Some manufacturers mix gel, copper, graphite, and charcoal with the memory foam to absorb and move heat out of the mattress. Other brands adjust the cell structure of the foam to create larger than average cells that let more air circulate through each layer. Some manufacturers add grooves, cuts, or channels in the memory foam for better air circulation.

The second potential problem of memory foam is slow responsiveness. Memory foam slowly bounces back to its original shape. That slow response to movement may leave some sleepers feeling stuck in their own body impression. Some manufacturers have developed high-density memory foams with better responsiveness. Other manufacturers layer poly-foam or latex underneath the memory foam to enhance the responsiveness of the top layers.

Latex Mattresses

Latex has a bouncy, springy feel in comparison to memory foam, yet it contours and cushions the body much in the same way. Mattresses may contain natural, synthetic, or blended latex.

Natural latex is made from the sap of the rubber tree. After harvesting, it’s made into either Dunlop or Talalay latex. Dunlop latex’s dense, firm feel works well in the support layers of a mattress. However, it’s sometimes used in comfort and transition layers, too. Talalay latex has a lighter, springier feel than Dunlop, which means it’s almost exclusively used in the comfort and transition layers of mattresses.

Synthetic latex is made from petrochemicals. It’s less expensive to make than natural latex but has a shorter lifespan. Blended latex is a mix of natural and synthetic latex. The ratio of natural to synthetic latex varies from manufacturer to manufacturer. Keep in mind that the higher the content of natural latex, the better the durability.

Latex mattresses contour to the curves of the body without necessarily filling them the way memory foam does. It’s excellent at relieving pressure and reducing motion transfer even though it has a springy feel. Latex bounces back into its original shape quickly, an appealing feature for combo and side sleepers. It’s also a great material for side and back sleepers. Stomach sleepers will need a firm latex mattress to reduce pressure in the lower back.

Like memory foam, latex traps heat. It should be made with aeration channels to allow heat and air to circulate. It’s also one of the most expensive materials used to make mattresses, especially natural latex. However, many manufacturers combine latex with memory foam or poly-foam to offset the cost.  In that case, the sleeper gets some of the benefits of latex without the heavy price tag.

Innerspring Mattresses

Innerspring mattresses have a coil support system with a quilted cover for cushioning. The coil type—Bonnell, offset, continuous, or pocketed coils—affects the feel and durability of the mattress.

Bonnell coils are traditional hour-glass shaped coils with a rounded head. They’re inexpensive but wear out quickly. Offset coils have the same shape as Bonnell coils, except they have squared off heads that contour better to the body. Continuous coils are made from a single piece of wire that interconnects every coil. Continuous coils are strong, but they transfer motion and can be noisy.

Pocketed coils are the same diameter from top to bottom, and each one is wrapped in an individual piece of fabric. They aren’t interconnected and only flex at high-pressure points. Because the coils flex independently of each other, there’s less motion transfer than with the other types of coils.

The thickness or gauge of the coils determines their firmness. High gauge coils are made of thinner wire and, therefore, give more easily under pressure. Thick, low-gauge wire doesn’t flex as easily, giving it a firmer feel. Some innerspring mattresses have a zoned support system, wherein coils of different gauges are used to support different areas of the body. For example, high gauge coils relieve pressure at the shoulders and hips while low gauge coils support the lower back and legs.

Coils have a firmer feel than memory or latex foam even if the mattress is of a similar firmness level. Innerspring mattresses are bouncy and responsive, but don’t conform to the body and may transfer a lot of motion. They’re best for back and stomach sleepers who tend to prefer a firmer mattress. Side sleepers and combo sleepers may find an innerspring mattress too stiff and firm at the shoulders and hips.

Hybrid Mattresses

Hybrid mattresses combine the cushioning of foam with the support of coils. A hybrid must have at least a two-inch comfort layer to qualify as a hybrid. Many hybrids have far more cushioning than that. The comfort and transition layers may be made of memory foam, latex, or poly-foam in various thicknesses or layer orders to achieve the desired feel.

Hybrid mattresses almost always have pocketed coils. Their ability to target high-pressure areas lets sleepers get a more customized sleep experience.

Hybrids can be expensive, heavy, and the coils usually wear out faster than the foam layers. However, side, back, and combo sleepers can all find comfort on this mattress type as long as it has the right firmness level. Couples who have differing comfort preferences may also find hybrids are a comfortable compromise.

Mattress Budget

An entry-level king size mattress starts at around $400, while premium models go up to over $5,000. Entry-level models cost between $400 and $1,000. For the first few years, these models will probably have similar comfort to more expensive mattresses. However, their lower-quality materials don’t have the durability to last more than five years.

King mattresses that balance quality with price fall into the $1,100 to $2,500 range. These models will have high-density foams, cooling techniques, and high-quality, cooling fabrics. You’ll also find hybrid models with a balance of quality and comfort in this price range.

Premium king mattresses start at around $2,500. These models have intricate stitching and premium fabrics in the covers, high-quality high-density foams, and may contain certified natural and/or organic materials.

Sleeping Position

Each sleep position creates different pressure points and puts unique demands on a mattress. We’ll go over the comfort needs of the most common sleep positions.

Side Sleepers

Side sleepers need pressure relief at their shoulders and hips. However, they also need support at the waist and lower back to maintain a neutral spinal alignment—that’s why the best mattresses for side sleepers are usually medium in firmness.

Side sleepers generally sleep better on mattresses of medium to medium-soft firmness. As far as mattress types, foam mattresses—memory foam, latex, or poly-foam—are a natural fit for side sleepers. Memory foam conforms beautifully to the unique shape of the sleeper and deepens its pressure relief the longer the sleeper stays in the same position. Some hybrids have adequate pressure relief for side sleepers. Typically, most innerspring models are too firm for side and combo sleepers.

Back Sleepers

Back sleepers have an advantage in that their spines naturally stay in a neutral position. Memory foam, latex, hybrid, and innerspring mattresses can all be a comfortable fit for a back sleeper. No matter the type of mattress, it should support the lower back and cushion the rest of the body to eliminate any painful pressure points.

If you suffer from back pain, medium-firm mattresses have been shown to be helpful. Those that suffer from other aches and pains may want to try memory foam or latex because of their ability to adapt and conform to the body’s shape.

Stomach Sleepers

We don’t recommend sleeping on your stomach because of the pressure it puts on the lower back. However, if you can’t help but sleep on your stomach, look for a firm mattress that prevents your hips from sinking into the mattress.

Stomach sleepers also need some cushioning at the shoulders that allows them to sink slightly, which prevents bowing in the lower back. Innerspring and hybrid models work well for stomach sleepers, but a firm memory foam or latex model can be comfortable for those who like to sleep in rather than on the mattress.

Sleeping Cool and Airflow

Mattresses with temperature regulation technology prevent overheating and help you sleep better. If you overheat, it can interrupt your sleep cycle, not only waking you but making it difficult to fall back asleep.

Memory foams with advanced or enhanced cell structures have more space for air to circulate. Other memory foams may have foams mixed with gel, graphite, charcoal, or copper. These additives absorb heat and move it out of the mattress.

best king size mattress

Both hybrids and innerspring mattresses have an advantage when it comes to airflow. The space around their coil support cores lets air and heat move and ventilate. Both types of mattresses tend to sleep cooler than foam models.

Common Questions

What is the best mattress for a king size bed?

Any of the five mattresses on our list would make an excellent choice. However, your personal preferences and circumstances will influence the type, brand, and mattress model that’s right for you. If you share a bed with a partner, a mattress that isolates motion and caters to both partners preferred sleep positions would be the best choice. For someone who sleeps warm, a breathable mattress would be a top option.

How do I pick the best mattress?

Start by knowing your preferred sleep position. That will narrow down the types of mattresses that are likely to appeal to you. Next, ask yourself a few key questions like:  Do I sleep warm? Do I like to feel the mattress around me, or would I rather sleep on top of the mattress? Do I like bouncy coils? The answers to these questions will narrow down your search.

Finally, make a list of the factors that are most important to you like breathability, motion isolation, or deep cushioning. Continue to narrow your options by eliminating the mattresses that don’t have the factors at the top of your list. You may need to go to a showroom or two and try a few mattresses to see how you respond to their feel. Eliminating the beds that don’t meet your sleep needs will eventually lead you to the best mattress for yourself.

What are the worst mattresses?

You can use a few common indicators to identify low-quality mattresses that aren’t likely to be comfortable for long, if at all. Watch out for low-quality foams because they tend to quickly sag or get body impressions.

No warranty or an exceptionally short warranty is a warning sign. The average mattress warranty lasts ten years. A shorter warranty may indicate a low-quality mattress. If the mattress doesn’t come with any warranty at all, you might want to skip it altogether.

When looking for a new mattress, you not only need to consider your sleep position, but your bodyweight, too. Petite sleepers weighing less than 130 pounds usually need a plush, soft mattress because firm models don’t flex under their body weight, which can create pressure points. At the same time, people weighing over 230 pounds need the support of high-density foams, low gauge coils, and an overall firmer mattress.

If you consistently sleep hot no matter the season, a foam mattress may not be a good choice for you. You may need the breathability of a hybrid or innerspring to prevent overheating.

What is the best mattress for back problems?

According to a 2015 study, the best mattresses for back pain have a medium-firm feel. The study specifically suggests airbeds since you can adjust their firmness by adding or removing air. Memory foam and latex mattresses are also good choices because they mold themselves to a sleeper’s body, providing thorough back support.

Which is better, a memory foam or spring mattress?

Both memory foam and spring mattresses have advantages and disadvantages. Of the two types, memory foam mattresses usually have higher customer ratings. Innerspring mattresses often can’t provide the pressure relief needed for a restorative night of sleep.

The Bottom Line

  • King size mattresses have the same layers and comfort features of smaller mattresses only on a larger scale.
  • Choose your mattress based on your preferred sleep position, body weight, and personal comfort preferences.
  • Be ready to spend more for a high-quality king size bed.

A king size mattress lets you spread out when you sleep. There are plenty of options out there. Take into account your unique circumstances, make sure your chosen mattress has the quality to last, and get ready for an incredible night’s sleep.

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