Best King Mattress: Reviews and Buyer’s Guide

You spend around a third of your day in bed, so the right mattress is a smart investment. If it’s time to buy a new mattress, we’re here to help. We’ve rounded up our picks of the best king mattresses you can buy online in 2019.

Best King Mattresses

BrandModelHighlightsPrice (Queen)
Amerisleep AS3 MattressAmerisleep AS3Features pressure-relieving Bio-Pur® and HIVE® technology to promote healthier sleep$1499
Zoma Sleep MattressZoma MattressContains cooling gels and dynamic support technologies $850
vaya mattressVaya MattressBudget-friendly king size option fit for all sleepers$667
Purple HybridMattressPurple Hybrid Contains proprietary Purple Grid™ to offer "No-Pressure" support $1899

1. Amerisleep AS3

Best Memory Foam Mattress for Side SleepersWhen searching for the best king mattresses, the Amerisleep AS3 is a popular choice.

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 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. 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.

If you’re looking for a mattress company with eco credentials, Amerisleep is one to consider.

Their mattresses feature plant-based memory foam. Plus, their foam is made using a process called variable pressure foaming (VPF), which creates virtually zero emissions. The company is also committed to recyclable packaging and recycles returned mattresses.

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 $1,499.

2. Zoma Mattress

Zoma sports mattressThe Zoma Mattress was designed with athletes in mind.

The Zoma Mattress boosts muscle recovery and athletic performance. The gel-infused memory foam contours to your body to relieve pain points more effectively. Combined with 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 $850.

3. Vaya Mattress

vaya mattressThe Vaya Mattress is a great bed for those on a budget, as it costs less than $700 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).

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.

4. Purple Hybrid

The 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.

How to Buy the Right Mattress Online

If this is your first time buying a mattress online it can be daunting. Some mattresses can be tried out in-store, but most 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.


Before 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.


The 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.


There are lots of mattress types, including foam beds, hybrids, and innerspring mattresses. Many bed in a box mattresses 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 Warranties

As 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.

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.

Medical Disclaimer: The information contained on the site should not be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for informational purposes only.

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