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

Are you and your spouse feeling crowded or uncomfortable during the night? Do your kids frequently climb into bed with you and force you to the edge of the mattress? If so, it may be time to upgrade to a king size mattress. May couples start with a queen size bed, but over time, this size can start to feel inadequate.

A king mattress will give both you and your spouse (and your children) plenty of room to stretch out and sleep comfortably. This article will take a took at 8 of the top king size mattresses on the market. Plus, we’ve included a comprehensive buyer’s guide to make shopping for your new king size bed less complicated.

Best King Size Mattresses

1. Amerisleep AS3

Amerisleep offers five different memory foam mattresses, each with a different firmness. Their AS3 model is our recommendation because the medium firmness is ideal for couples and most sleeping positions. Plus, it comes with a unique transition layer that provides the perfect balance of cushioning and support.

Amerisleep’s proprietary foam, Bio-Pur®, makes up the top layer of the AS3 and provides plush comfort that contours to the body. Traditional memory foam tends to trap heat and can also give off a harsh chemical smell.

Amerisleep’s Bio-Pur® foam offers more breathability, plus it is cleaner and less toxic than most memory foams. The CertiPUR-US® certification ensures little to no “off-gassing” when you bring the mattress home. Amerisleep creates this foam by substituting plant-based oils with some of the petroleum-based oils. This unique memory foam provides a more comfortable and safer sleep surface.

Beneath this foam is a transition layer featuring HIVE® technology. This layer is zoned to provide a deeper compression near the hips and shoulders, and more firmness under the back, neck, and head. HIVE® is also responsive enough to prevent excessive sinking, so the spine always remains in a neutral position.

Supporting these advanced layers is Amerisleep’s Bio-Core® base foam. This durable foam prevents sagging and indentations, so your new bed will support you for years to come.

To ensure your comfort and satisfaction, the AS3 comes with a 100-night sleep trial and a 20-year warranty.

2. Zoma Mattress

When your muscles and joints are supported, they can repair and rebuild quickly. The Zoma Mattress was originally designed for athletes. But its creators soon realized that everyone could benefit from deep, restorative sleep.

The comfort layer of this mattress features pain-relieving memory foam with Triangulex™ technology. This technology cradles sensitive areas but also keeps the heavier parts of the body supported on the mattress. This support keeps the hips and shoulders properly aligned. The triangle cutouts on this layer also create more airflow, so you sleep cool throughout the night.

The Reactiv™ layer beneath Triangulex™ increases responsiveness—you stay supported even when changing positions. Plus, this layer provides motion isolation to cut down on nighttime disturbances. The Support+ foam in the base of this mattress is high-density and provides attentional spinal support and durability.

Zoma offers a 100-night sleep trial to give you ample time to test out the mattress. They also include a 10-year warranty for any manufacturer defects.

3. Amerisleep AS5 Hybrid

In addition to their memory foam mattresses, Amerisleep also offers three hybrid mattresses. If you prefer a soft mattress but also enjoy the slight bounce similar to an innerspring bed, the AS5 Hybrid is a perfect choice.

This mattress features 3-inches of Bio-Pur® foam in the top layer, but the base of this bed includes a patented spring coil system. These coils are individually wrapped to ensure comfort and prevent pressure points. Plus, this base is zoned to give added support to vulnerable areas such as the lumbar. When the lumbar is adequately supported, sleepers experience less back pain and stiffness.

Because soft mattresses tend to sink, Amerisleep includes a layer of Active Flex foam above the spring coils. This layer prevents sinking and quickly reforms to your shape as you move during the night.

Like all of Amerisleep’s mattresses, the AS5 Hybrid has a 100-night risk free sleep trial and a 20-year warranty.

4. Zoma Hybrid

The Zoma Hybrid features the same restorative benefits as Zoma’s classic memory foam mattress. The main difference is the added bounce and breathability from the bed’s pocketed coils. Zoma wraps all of the hybrid’s coils in fabric packets to reduce noise and isolate movement.

The 12-inch mattress contains the same comfort foams that are found in the Zoma Mattress.

The top layer is malleable memory foam that can mold to your every curve. Foam cutouts are arranged in three zones for targeted support. The mattress’s head and foot feature cutouts to increase contouring, while the midsection remains free of cutouts for more support.

A layer of Reactiv™ foam transitions between the comfort layer and supportive coils. Reactiv™ lifts you, preventing the sinkage that can lead to spinal misalignment and back pain. When you get off the bed, Reactiv™ helps the mattress snap back into shape.

Every Zoma Hybrid mattress includes a 100-night sleep trial and a 10-year warranty.

5. Vaya Mattress

The Vaya Mattress features two hypoallergenic foam layers ideal for allergy sufferers. Vaya foam also offers a slight bounce similar to latex foam. This responsiveness provides a balance of support and lift.

With its soft, breathable cover, body heat is circulated away from the bed to prevent overheating. Soft memory foam in the comfort layer offers more breathability and hugs the body for pressure-free support. The support foam in the base of the mattress is a higher density foam to keep the bed even and prevent sagging.

Both foam layers have a CertiPUR-US® certification to ensure a low VOC emission. Plus, the Vaya Mattress pairs well with most popular bed frames, including slatted frames, box springs, and adjustable bases.

Vaya offers a 100-night sleep trial and a 10-year warranty.

6. Avocado Green Mattress

If you are in the market for an organic mattress, look no further than the Avocado Green Mattress. This mattress is a hybrid of latex foam and innerspring coils. Plus, the materials in this bed have earned GOTS and GOLS organic certifications.

Beneath a quilted organic cotton cover is 3 inches of GOLS certified latex guaranteed to be free of harmful pesticides. With this mattress, you also have the option of adding their Euro-style pillow top for an additional 2 inches of luxury firm comfort. This topper comes in either a soft, plush option or a firm option.

The support layer of the Avocado Green features 1,414 spring coils. These coils are zoned to be more flexible around sensitive areas, so you never experience painful pressure points. The perimeter of the mattress has reinforced edge support to cut down on motion transfer and make moving around the bed more comfortable.

The Avocado Mattress offers a 10-year sleep trial and a 25-year warranty.

7. Bear Pro

The Bear Pro features three different technologies designed for temperature control. This gel memory foam includes a copper infusion and a Celliant® cover to wick heat and moisture away from the body as you sleep.

The Celliant® fibers in the cover absorb moisture and speed up muscle recovery by increasing local circulation. The comfort layer contains two types of memory foam—one includes a cooling gel foam, and the other features a copper infusion. The gel beads keep you cool by absorbing heat. Since copper is antiviral and antibacterial, the mattress stays clean and germ-free. The transition layer and high-density base increase responsiveness and promote a healthy spine.

Bear offers a 100-night sleep trial and a 10-year warranty.

8. Nolah Signature 12

Most foam mattresses can’t be flipped because they have a higher density foam in the base. But Nolah’s Signature 12 inch includes its high-density support layer in the middle of the mattress, so you still get the option of flipping the bed.

This mattress is also customizable. One side of the bed features 2.5 inches of Nolah’s soft cooling AirFoam™ for pressure relief and contouring that also keeps you cool. Under this soft layer is a latex foam layer to create a slight bounce to keep you lifted on the mattress.

The other side of the bed includes 1 inch of the AirFoam™ but offers a firmer feel, so sleepers can choose which firmness is right for them. In the middle of the bed is 7 inches of high-density foam that supports you no matter which firmness option you choose.

The Nolah Signature 12 inch comes with a 120-night sleep trial and a lifetime warranty for any manufacturing defects.

9. Purple Hybrid Premier

Although Purple started with one all-foam mattress, they now offer two hybrids. Their Hybrid Premier combines their Purple Grid and a supportive innerspring coil system.

The cover of the Hybrid Premier features a stretch knit fabric to keep air moving throughout the bed. This cover allows sleepers to feel the supportive Purple Gird just beneath the surface. The Purple Grid is made of a uniquely flexible gel material called Hyper-Elastic Polymer®. This material reacts to intense pressure. When pressure is light, the Purple Grid responds accordingly, so you always experience just the right amount of comfort. With the Hybrid Premier, you have the option of including either 3 or 4 inches of the Purple Grid. Supporting this layer is a 7.5-inch coil support base wrapped for additional comfort and durability.

Purple’s Hybrid Premier comes with a 100-night sleep trial and a 10-year warranty.

Types of King Size Mattresses

Once you’ve decided to buy a king size bed, you will need to determine which type of king will fit your needs. Many people may not realize that there are several variations of a king size bed. Below, we break down the measurements for each king mattress and explain why it might be beneficial for you.

King

76 inches by 80 inches

A standard king size mattress (also called an eastern king) measures 76 inches by 80 inches. This mattress is the same size as two twin xl mattresses (38 inches by 80 inches). A king is wider than a queen size (60 inches by 80 inches) by 16 inches. But both king and queen size mattresses measure 80 inches in length.

California King

72 inches by 84 inches

California king mattresses are 72 inches by 84 inches, so it is 4 inches shorter in width but 4 inches longer than a king size. The extra length makes this size ideal for those over 6 feet tall or those who prefer extra legroom.

Wyoming King

84 inches by 84 inches

Wyoming king size mattresses measure 84 inches by 84 inches—giving it the same length as a California king but 12 more inches in width. This size is ideal for larger couples who may also prefer to co-sleep with children. However, Wyoming kings are not available at most stores or online retailers in the U.S.

Texas King

80 inches by 98 inches

A Texas king (also called a grand king) measures 80 inches by 98 inches, so it is wider and longer than a California king and has more length than a Wyoming king. But these mattresses can also be difficult to find and may be more expensive.

Alaskan King

108 inches by 108 inches

An Alaskan king is the largest mattress you can buy—it measures 108 inches by 108 inches. This massive bed allows very tall sleepers plenty of legroom without having to worry about hanging off the bed. It also affords families who like to co-sleep extra room, so no one has to sleep cramped or close to the edge. Like Wyoming and Texas kings, these mattresses are not as popular as standard kings. So, they can be difficult to find.

Split King

Two twin xl mattresses (38 inches by 80 inches)

A split king is two twin xl mattresses (38 inches by 80 inches) placed side by side to create one standard size king. Most couples have different preferences when it comes to comfort. A split king allows couples to select a different firmness for each side of the bed. This option gives you both the perfect comfort level for your preferred sleep position. A split king can also cut down on motion transfer across the surface of the bed so you won’t disrupt your partner during the night.

Benefits of a King Size Mattress

As you can see for the list above, there are mattresses larger than a standard king, but many of these beds are hard to locate and may hurt your budget. A standard king size mattress is a great option for couples who have outgrown their queen size bed.

The larger size provides plenty of room to stretch out and can accommodate children who may crawl into bed with you. The greater surface area can also reduce nighttime disruptions if your partner tosses and turns during sleep. While standard kings are often easier to find than California kings, many popular brands also offer a Cal king option.

If you have a standard 11 by 12-foot bedroom (132 square feet), a king mattress may be too big for this space. But, if you have a master bedroom or something larger, anything smaller than a king may look awkward. Most master bedrooms measure 14 by 16 feet (224 square feet). So a king or a California king will fit well into this space and still affords you room to move around the bed.

Mattress Firmness

Mattress firmness is rated on a scale of 1 to 10—with 1 being the softest and 10 being the firmest. Your sleep position and body type are a good sign of the firmness level you’ll find most comfortable.

• Soft mattress (1 to 2 on the firmness scale): Works best for lightweight sleepers and side sleepers. Since lightweight sleepers tend to sink less, they need a soft mattress to experience contouring.

• Medium-Soft Mattress (3 to 4 on the firmness scale): Suitable for lightweight sleepers and side sleepers. This firmness will cushion the hips and shoulders when side sleeper, but will also prevent sinking, so the spine stays in a neutral position.

• Medium mattress (5 on the firmness scale): A true medium is ideal of side sleepers, combination sleepers, and couples. This firmness offers a balance of both cushioning and support. So, even as you change positions throughout the night, your spine will remain in a good position. A medium is suitable for most sleep positions, so couples with different preferences find this firmness to be a good compromise.

• Medium-Firm Mattress (6 to 7 on the firmness scale): Works well for heavy sleepers, back sleepers, and those with back pain. The increased firmness prevents heavier sleepers from sinking too far into the bed, which can force the spine out of alignment.

• Firm Mattress (8 to 10 on the firmness scale): Firm mattresses are suitable for stomach sleepers, back sleepers, and heavy sleepers. The firmness will prevent the chest from sinking when stomach sleeping and will keep the hips and shoulders aligned when back sleeping.

Mattress Types

As you shop for a new king size mattress, you will come across several different mattress types. King mattresses don’t just vary in dimension, but they may also feature different materials and support systems. To give you a better idea of what is available, we break down the four most common types below.

Memory Foam Mattress

Memory foam mattresses support your entire body without any added pressure so you can experience a weightless sleep. When resting on this “cloud-like” surface, your muscles will have time to recover, and joints can rest comfortably. With the right firmness, a memory foam mattress will keep your spine in a neutral position and prevent pressure points.

But, memory foam can vary in terms of quality. Traditional memory foam tends to trap heat, but those with an advanced open-cell structure are more breathable. Additionally, those made with partially plant-based oils are cleaners and less toxic.

Latex Foam Mattress

Latex foam provides contouring similar to memory foam but also has a slight bounce that causes you to feel more lifted, rather than cradled. Latex foam is eco-friendly and sustainable because rubber trees (the source of latex) do not have to cut down for harvesting. Latex foam is also hypoallergenic, antibacterial, antimicrobial, and resistant to dust mites—making latex foam mattresses are an excellent option for allergy sufferers.

Hybrid Mattress

Hybrid mattresses have a comfort layer 2 to 3 inches thick. This layer usually features memory foam or latex foam. Beneath the comfort layer, hybrids have a support base of individually wrapped spring coils. Coils are often zoned to provide a balance of cushioning and support, so it is firmer near the back and neck, but softer near the hips and shoulders.

Innerspring Mattress

Innerspring mattresses have been around for many years. These beds have a support base of steel coil springs padded with other materials such as cotton, wool, or foam. Some innerspring mattresses may contain foam in their top layer for added comfort, but this layer is typically only 1 inch thick.

Since innerspring mattresses have more space between coils, dust and dirt can often collect in these mattresses. This debris can cause breathing issues for those with allergies or asthma. Some spring coil systems are not as durable as an all-foam support base. These springs often become broken or bent and may stick up into sensitive areas—resulting in painful pressure points. Although innerspring mattresses remain popular due to their low price point, they do not offer the support of memory or latex foam.

Sleep Trials, Warranties, and Return Policies

Purchasing a king size mattress is an important decision. To ensure that you are getting the most out of your investment, you will want to ensure that you have time to try out the bed before committing.

Sleep Trial

In most cases, it takes anywhere between two weeks to a month to become accustomed to a new mattress. So, you will want a sleep trial that allows you time to test out the bed for at least 30 days. An adequate sleep trial period is not hard to find since most bed-in-a-box mattress brands offer trials between 90 to 120 nights.

This trial period lets you test the mattress while in the comfort of your own home and ensure it’s right for you. When shopping at a mattress store, pushy sales associates often hover nearby while you test out the bed. This process can cause you to feel pressured into making a decision. Plus, the in-store experience doesn’t afford you much time to sleep on the mattress. With a trial period, you get plenty of time to find out if the best is right for you. If it’s not right, most companies are happy to provide a full refund or let you try out a different model.

Warranties

Most brands stand by the quality of their product by offering a warranty to cover any manufacturing defects such as sagging or indentations. Most brands offer a 10-year warranty, which is roughly the lifespan of most high-quality mattresses.

But it’s important to note that mattress warranties do not cover customer misuse, such as water damage from spills. So, it is helpful to protect the surface of your bed with a mattress protector.

Return Policies

A sleep trial affords more time to test the bed, but if the bed doesn’t come with a sleep trial, the brand may include a return policy. Most mattress return policies last around 30 days and will provide you with a full refund if you are unhappy with the bed. Although a 100-night sleep trial is ideal, a 30-day return policy will also help you make the best choice.

Other Things to Consider

What is the best king mattress to buy?

Mattresses are not one size fits all. The right firmness and size will vary from person to person. In terms of comfort, the best mattress for you will depend on your body type and preferred sleep position. Our firmness guide listed above can help you locate the right comfort level for your needs. Reading mattress reviews is another way to determine what type of comfort the bed provides. Customer reviews offer valuable insight into the firmness and overall support of the mattress.

In terms of size, a standard king is suitable for most couples and those under 6 feet. Larger couples and those taller than 6 feet may find a California king more comfortable.

What is the top-rated mattress for 2021?

Mattress comfort is subjective, but customer satisfaction reviews for memory foam beds tend to be among the highest. Memory foam mattresses offer superior comfort and pressure-free support. So, they work well for those living with chronic pain or those who are recovering from injury.

What is a good price for a king size mattress?

A king mattress can cost anywhere from $850 to $3,000. But the cost will fluctuate depending on the type of mattress and the materials used. Hybrids cost more than memory foam mattresses, and latex beds are typically more than memory foam beds.

Are all king size mattresses the same size?

No, there are variations of the king size like the California king, Texas king, or Wyoming king, and each has different dimensions than the standard king size. California kings are a big longer than standard kings, while Texas and Wyoming kings are considered oversized mattresses for their huge dimensions.

How much do oversized king mattresses cost?

It all depends on how big you go, there are some beds like the Texas king that are just slightly larger than kings, while Alaskan kings are a whopping 108 inches wide by 108 inches long. These beds vary in price since they range so drastically in size, but customer reviews mention paying anywhere between $3,500 to $7,000 for an oversized king bed.

Conclusion

If you and your spouse are feeling cramped in your queen size mattress, upgrading to a king is a sure-fire way to find better sleep. If you’re a solo sleeper and prefer plenty of room to stretch out in bed, a king is also a great option. Although kings do come at a higher cost, most people find the extra space well worth the investment. Plus, if you have a larger bedroom, a king will help to fill out the space comfortably. The tips included in this guide will help you find the right size and firmness for a good night’s sleep.