King size firm mattress in a box

The CNET sleep editors have tested over 100 mattresses, and they rounded up some of the best king-size mattress options on the market to help you narrow down your search. Whether you're looking to upgrade to a king bed, or you need to swap out your current mattress for something more modern, our best king-size mattress review likely has a good match for you. 

Check out our size guide to compare mattress sizes. And if you're looking to upgrade your whole sleep setup, we have suggestions for sheetspillows and other sleep essentials

Video: Best king mattress for 2022

Watch CNET Video Producer Owen Poole review the best king mattresses for 2022.

Read more: Best California King Mattresses for 2022

King size firm mattress in a box

Brooklyn Bedding

Brooklyn Bedding Signature

Best king size mattress

2023

Type

Hybrid mattress

Firmness

3 firmness levels | Soft: Medium-soft to soft or 2 | Medium: Medium to medium-soft or 4 | Firm: Medium-firm or 7

Trial

120 nights

Warranty

10-year limited warranty

Kinging off our best king size mattress review is the Brooklyn Bedding Signature mattress. It fits the bill for your average sleeper looking for a quality king bed that won't cost an arm and a leg. What really impressed me about this one, even though this is a high quality hybrid mattress, it costs less than the foam Casper. That's pretty uncommon since hybrid beds are typically more expensive than all-foam ones, so it offers a really great value. 

It's offered in three different firmness levels, giving you the option to cater exactly to your primary sleeping position. It's suitable for all sleepers from back, stomach, side and combination. I really liked the firm option because it sat around a medium-firm, and I'm a stomach sleeper who needs that additional support. However, side sleepers may want to consider the medium or soft model instead for more plushness. 

Brooklyn Bedding Signature also has a hybrid construction containing almost 1,000 pocketed coils, making it durable and supportive enough for any body type from petite to heavy. If you're looking for a quality king bed at a very reasonable price, this is a great pick.

Read our Brooklyn Bedding Signature Hybrid review.

 

Brooklyn Bedding Signature Hybrid

$1,599 at Brooklyn Bedding

King size firm mattress in a box

Lindsay Boyers

Saatva Classic

Best firm king size mattress

Type

Hybrid mattress

Firmness

3 firmness levels | Plush Soft: Medium or 5 | Luxury Firm: Medium-firm or 7 | Firm: 9/10 or firm

Trial

360 nights

Warranty

Lifetime warranty

The Saatva mattress is a luxury bed with an ultra supportive design that you don't get from every online mattress. It includes two innerspring layers; One layer is a system of extra strong dual coils and another is a thinner layer of pocketed coils for additional support and improved motion isolation. 

The middle portion of the Saatva mattress also has "lumbar zone technology," or a series of wires that add extra support for the memory foam to keep your spine properly aligned. Combined with its firmer profile options, the Saatva ends up being a durable, supportive and firm mattress. Although, the thick and fluffy pillow top does make it feel more plush and pressure relieving. 

The Luxury Plush model falls more around a medium, while Luxury Firm and Firm are around a medium-firm and firm on the scale. The firm and medium-firm Saatva mattresses are some of the best mattresses if you're looking for a premium king size bed at a fair price. 

The only knock is that this mattress has more motion transfer than the others because of the multiple coil layers, so if you sleep with someone who moves around during the night, there's a good chance you're going to feel it. Read more in our full Saatva mattress review. 

Saatva Classic

$200 off of $1000 purchase

$2,195 at Saatva

* Pricing based on Queen model

King size firm mattress in a box

Allswell

Allswell mattress

Best affordable king mattress

You may not be familiar with Allswell, but you're likely familiar with its parent company Walmart. As its entrance to the bed in a box game, Walmart introduced the affordable Allswell mattress. It's a hybrid mattress made with both foam and coils, and hybrid beds tend to be a little more expensive than your average bed. However, the Allswell mattress is a good hybrid mattress for the price of a low-budget foam mattress, giving it a well-deserved spot on this best king bed list. 

It's a tad on the firm side, I'd rate it around a medium to medium-firm. For that reason, I'd primarily recommend it to back, stomach and combination sleepers.

Inside is a simple construction with a foam base layer, 6-inch thick pocketed coil system and a poly foam top layer. It is quick to respond to pressure and you sit more on top of the bed than you do inside. If you're a combination sleeper, this is music to your ears because it doesn't give resistance like memory foam does when you switch positions. Also, thanks to its hybrid construction, it's suitable for all body types.

In short, the Allswell mattress is a generally accommodating mattress that sells for a great price. Read more in our Allswell mattress review. 

$539 at Allswell Home

King size firm mattress in a box

Nectar

Nectar Premier

Best king size memory foam mattress

Type

Memory foam mattress

Firmness

5 or medium

Trial

365 nights

Warranty

Forever warranty

The Nectar Premier mattress is the replacement for the mattress company's upper-level model called Nectar Lush. The Nectar Premier mattress has a thick memory foam construction, giving it a relieving and slow-responding memory foam feel. It takes a few seconds for your body to activate the foam, but once it does, the memory foam slowly contours around your curves and nestles you into the bed. 

It's the best king size bed for people who want the traditional memory foam feel you can find in a Tempur-Pedic mattress at a more wallet-friendly price. 

This Nectar mattress is also entirely made out of foam, so you won't get that bouncy and responsive feel that hybrid beds can provide. Inside the bed's gel memory foam comfort layer is a phase-change material that helps keep your temperature neutral, unlike old memory foam beds that are notorious for retaining heat. For even more cooling abilities, you can also take a look at the Nectar Premier Copper model. 

I think Nectar Premier falls around a 6 out of 10 on the firmness scale, making this king mattress suitable for most sleeping positions, especially back or stomach sleepers. If you're a side sleeper under 150 pounds, however, it might not be soft enough for what you need. The memory foam nature of this mattress will also give some resistance to combination sleepers who switch positions during the night. Read more in our full Nectar Premier mattress review. 

NOTE: The US Product Safety Commission recently issued a recall for Nectar Premier king- and queen-size mattresses manufactured on Sept. 24, 2021. Look for a model number CHILL and Prototype ID:ECS2003RHCH on a tag on the bottom of your mattress to find out if yours has been recalled. We have reached out to Nectar for comment and will update the story if they respond. 

Nectar Premier

$1,199 at Nectar Sleep

King size firm mattress in a box

Amerisleep

Amerisleep AS2 Hybrid

Best king size mattress for back pain

The Amerisleep AS2 Hybrid has a lot going for it and stands out from other competing memory foam bed-in-a-box mattresses. It's one of the best king mattress picks for people with back pain because of its accommodating features, extra bells and whistles and affordable price. 

People with back pain typically are most comfortable on beds with a medium-firm profile, and ample pressure relief to properly support the spine without being too firm. The AS2 Hybrid mattress fits that bill, and its advanced pocketed coil layer with firm edge support reinforcements makes it even more supportive and helps prevent against sagging.

Within the bed's comfort layers you can find Amerisleep's special Bio-Pur memory foam and Affinity Transition layer. The Bio-Pur has an open-cell structure so it's more breathable than your typical memory foam and really contours around the curves of your body, giving you a big foamy hug. The Affinity layer, however, provides a firmer more supportive feel for additional back support. 

Last but definitely not least is Amerisleep AS2 Hybrid's Celliant-infused cover. The special fabric absorbs your body heat and transfers it back to your body as infrared energy. It's purpose is to help boost circulation, assist in the body's recovery process and leave you feeling more refreshed in the morning. Only a handful of mattresses have this tech, such as the Bear Original mattress. For more info on the cover and the AS2 Hybrid, check out our full Amerisleep mattress review. 

If you catch this mattress on sale, a king size falls under $1,500. For comparison, other king mattresses for back pain can go for $1,800 and up. 

$1,949 at Amerisleep

King size firm mattress in a box

Layla Hybrid

Best king size mattress for side sleepers

2023

Type

Flippable hybrid mattress

Firmness

Firm: 5 or medium | Soft: 3 or medium-soft

Trial

120 nights

Warranty

10-year limited warranty

In a sea of bed-in-a-box mattresses, brands have to add a little sauce to their designs to make them stand out. The Layla Hybrid is unlike most other hybrid mattresses because it comes with a two-in-one deal. What I mean is that it's flippable, and you can sleep on each side of the mattress comfortably. 

The soft side is perfect for side sleepers who want an ultralight yet plush feel. I rate it around a medium-soft or a 3 out of 10 on the firmness scale. On the flip side, the firm profile of Layla isn't a true firm. It's more like a medium to medium-firm or a 6 out of 10 on the firmness scale. This makes it a good choice for most sleeping positions, but I also think it's a good pick for heavy side sleepers who want a soft feel with extra support. 

In the center of the Layla Hybrid is a system of strong pocketed coils that act as the support layer. The edges of the coils have even stronger, dual-coil design to make the perimeter of the mattress more supportive. The comfort layers of the soft side are made of two thick foam slabs including copper-infused memory foam to help regulate temperature. The firm side is made with the same materials, but firmer and thinner so you get a more supportive feel. 

The memory foam inside the Layla Hybrid is really pleasant. It's more light and airy than the typical dense, hugging memory foam I'm used to. It feels like you're laying on a big fluffy pillow that supports your back, and it's a great pick for side sleepers of all sizes looking for the best king mattress.

Read our Layla Hybrid review.

 

Layla Hybrid

$200 off Hybrid Mattress + 2 FREE Pillows

$1,499 at Layla

* Pricing based on Queen model

King size firm mattress in a box

Slumber Yard

Purple Hybrid

Best king size hybrid mattress

Type

Hybrid mattress

Firmness

7 or medium-firm

Trial

100 nights

Warranty

10-year warranty

The Purple Hybrid is a unique, yet comfortable mattress that combines strong pocketed coils and a gel-like material special to Purple. Rather than varying layers of memory foam, the Purple Hybrid has a Hyper-Elastic Polymer grid formation that's meant to absorb and relieve pressure. This Purple mattress seemed to have a magic ability to form around my body and perfectly cradle my pressure points, which not only made it immediately comfortable, but also had me waking up totally pain-free. I also can't forget to mention the gridlike design of the polymer allows for a ton of airflow, so it's one of the most breathable I've ever tested.

I rate this king mattress around a medium-firm and it has the firmest profile of the other Purple Hybrid mattresses, so I'd say this bed is best for combo, stomach and back sleepers who want back support sprinkled with ample pressure relief. It's also the most affordable from the Purple Hybrid lineup, which is an added plus for your bank account.

The Purple mattress also had the most bounce out of all of the mattresses on this best king mattress review, so if you're looking for a king bed that's responsive to pressure and quick to bounce back, this is an excellent option. Though, the grid did take a little while to get used to. It wasn't uncomfortable, but it was definitely different, so keep that in mind. There's an adjustment period with any new mattress, though, so it's not something that was totally unexpected.

Purple Hybrid 2

$1,899 at Purple

King size firm mattress in a box

Casper

Casper Original

Best king size mattress in a box

Type

Poly foam mattress

Firmness

6 out of 10 or medium

Trial

100 nights

Warranty

10-year limited warranty

For an entry-level king mattress that skips the hoopla and offers an affordable value, the Casper Original is a great option and could also be considered the best king size foam mattress. It's incredibly accommodating, comfortable and arguably the most popular bed-in-a-box mattress on the market. It has a simple three-layer construction that boasts a zoned support design, meaning it's firmer under your back where you need additional support, and pressure-relieving under your shoulders and trunk where your body needs pressure relief. 

It's not slow-responding like memory foam mattresses are. Instead, this bed responds quickly to pressure and I'd describe it as a basic, neutral feel; Like standard foam you might pull out from the cushions of your favorite comfy couch. The firmness level is also really accommodating, I'd rate it around a medium or 5 or 6 on the firmness scale. This makes it ideal for any sleeping positions from back, side, stomach, to combination.

The one downside about this bed is that it's probably not ideal for people over 230 pounds because it's not as supportive as it should be to last long-term for a heavier individual. There are plenty of Casper hybrid mattresses, however, that offer support, durability and the same signature Casper feel. There's a reason why it's so popular -- when you lay on it, most people will agree that it's a comfy bed.

Read our Casper Original review.

 

Casper Original

up to $600 off mattresses

$1,695 at Target

King size firm mattress in a box

Intellibed

Intellibed Signature Matrix Grand

Best luxurious king size mattress

Type

Mixed foam hybrid mattress

Firmness

Medium or 5

Trial

90 nights

Warranty

20-year warranty

Let's address the elephant in the room right away: This best king mattress pick is expensive. But if you have the budget for this mattress brand and you're looking for a way to invest in your quality of life, you won't be disappointed. The Intellibed Signature Matrix Grand is constructed of several layers, including a latex and foam layer, but the real star of the show here is the Gel Matrix technology -- something that was originally used in the beds in burn units to help alleviate pain while patients recovered. 

Without getting too technical, the Gel Matrix is an elastic gel that flexes and moves so that it's somehow firm and soft at the same time, giving you the best of both worlds. The firmness provides the support your body needs and keeps your spine in the proper alignment, while the softness allows some give to relieve your pressure points without sagging. And it truly does work.

When lying on the king mattress, I felt it give to my pressure points -- namely, my shoulders and hips -- while still keeping my body properly aligned, no matter which position I was in. As soon as I got comfortable in it, I could feel the pressure lifting away, almost as if I was in a zero gravity situation and, after a few weeks with it, I realized I was sleeping through the night consistently.

It's also the first king size bed that my boyfriend and I wholeheartedly agreed on. There were other king mattresses that we both really liked, like the Helix Midnight Luxe and the Purple Hybrid, but the Intellibed Signature Matrix Grand has completely squashed all mattress discussions and, to me, that alone is worth the price.

Intellibed Signature Matrix Grand

$8,999 at Intellibed

* Pricing based on Queen model

How we test king-size mattresses

CNET editors pick the products and services we write about based on editorial merit. When you buy through our links, we may get a commission. 

Testing a king mattress is similar to how we test most of our mattresses, and we pay attention to a handful of important factors. 

  • Firmness: The measure of how firm or soft a mattress feels is an important factor in deciding if a bed is suitable for you or not. Firmness, a lot of the time, indicates how pressure relieving or how supportive a mattress feels. Side sleepers usually like a softer mattress because it offers more give, therefore, more pressure relief around the hips and shoulder areas. Back and stomach sleepers, on the other hand, tend to sleep better on firm beds that keep the spine properly supported. We test firmness by using our judgment and deliberating amongst team members. It's easier to test firmness when you have 100 different mattresses to compare it to.
  • Construction and features: We take a close look at the construction of a mattress, which is a good tell on how it feels and how supportive it is for certain body types. We also consider any extra or special feature a mattress might have to stand out from the rest of the competition. Is it cooling? Does it have a special cover made with Celliant fabric or cashmere? Does it have an extra durable construction? We take all of this into consideration when testing mattresses and delegating best list picks. 
  • Performance: This refers to motion isolation, temperature regulation and edge support abilities. How well does a mattress perform when we put it to the test? We test motion isolation by having couples judge how it sleeps, or placing a glass of water at the end of the bed to see how much it shakes when we move. Edge support is tested by laying on the sides, bouncing and checking how sturdy it feels. Personal experience is also how we test temperature, with the help of a thermometer gun. 
  • Feel: Feel is a separate topic from firmness. This refers to how a mattress' materials are perceived. Is it dense and morphy like memory foam, neutral and soft like neutral-foam, or supple and bouncy like latex foam? We like to describe the feel as best we can since you're unable to feel it through your computer screen. 

Read more on how we test mattresses.

What to look for in a king mattress

When looking for the best mattress, you should take in some key considerations. You should follow the same guidelines when looking for a king-size bed, with a few key considerations. 

  • Hybrid vs. foam: The more you weigh, the more supportive your mattress should be. Hybrid beds are best for all body types, including those over 230 pounds, while foam beds are most ideal for people under 230 pounds. 
  • Firmness is a key indicator for how accommodating a bed will be. Like I said above, side sleepers should opt for medium to soft mattresses that offer ample pressure relief while back and stomach sleepers should consider medium to firm beds that offer enough support for proper spinal alignment. Medium beds right in the middle are perfect for combination sleepers. 
  • Key features like cooling tech, edge support reinforcements and Celliant covers can help you decide if a bed fits your lifestyle and circumstances. Strong edge support is great for couples who share a mattress, while beds with Celliant covers are perfect for people with active lifestyles. 
  • Price matters when looking for a king bed. The bigger the bed the more expensive it is. King beds are often more than $1,000, but there are budget options like Allswell to consider if you're looking for maximum savings. 

Who is a king mattress best for?

Not everyone needs a king size bed, but it is mighty convenient and comfortable during these situations:

  • Couples who want more space than a queen size offers
  • Taller people who don't want to feel cramped (queen beds are about 6.6 feet long)
  • Sleepers who share a bed with their kids (king beds are wider than California king beds)

King and California king mattresses are the most popular of the king variety, but there are a host of beds that are technically classified as king. Here's an overview of the different types of king beds if you're looking for something a little different. 

King size mattress types

TypeDimensionsStandard king (aka Eastern king)76 by 80 inchesCalifornia king72 by 84 inchesSplit kingTwo twin beds (36 by 80 inches)Split California kingTwo twin XL beds (36 by 84 inches)Alaskan king108 by 108 inchesWyoming king84 by 84 inchesTexas king80 by 98 inches

King size mattress FAQs

How much does a king-size mattress cost?

The average king mattress costs around $1,000 or more, depending on how premium of a mattress you're looking to buy. However, there are more affordable options available for around $500 for budget shoppers who are looking to pay a little less.

How big is a king-size mattress?

A king-size mattress measures out to 80 inches long by 76 inches wide and 4 inches thick. Compared to a queen-size mattress, it offers the same length but 16 more inches in width.

What is the best king-size mattress?

Typically, the best king-size mattress is a bed that's able to accommodate two sleepers because it's the most popular size among couples. Some of the best king beds have pocketed coils and reinforced edge support, can isolate motion well, and/or have a breathable design. Some of CNET's picks include:

  • Brooklyn Bedding Signature
  • Saatva Classic
  • Nectar Premier 
  • Purple Hybrid 
  • Layla Hybrid
  • Amerisleep AS2 Hybrid
  • Allswell 
  • Casper Original

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.

What is the best bed in a box to purchase?

The Best Mattresses in a Box.
Editor's Pick – DreamCloud..
Best Luxury Mattress in a Box – Helix Midnight Luxe..
Best Mattress in a Box for Couples – Nectar..
Best Hybrid Bed in a Box – WinkBed..
Best Mattress in a Box for Back Pain – Brooklyn Bedding Signature Hybrid..
Best Mattress for Back Sleepers – Nolah Evolution..

What is the best brand of extra firm mattress?

Quick look at the best extra-firm mattresses.
Best-rated extra-firm mattress: Plank by Brooklyn Bedding..
Best extra-firm foam mattress: Saatva Loom & Leaf Mattress..
Best extra-firm cooling mattress: Cocoon by Sealy Chill Mattress..
Best extra-firm mattress for back pain: Beautyrest Harmony Lux Carbon Series..

Is a very firm mattress good for your back?

A firm or extra firm mattress is beneficial to the health of your back by providing a level surface to the whole of your body while you sleep. This extra support helps your body maintain good posture and prevents your back from curving, which can happen on softer mattresses.

Are mattresses in a box good mattresses?

Mattresses in a box are just as durable as traditional mattresses. They're made of the same materials, like memory foam, gel foam, and latex. Even innerspring mattresses can be rolled up and shipped in a box. They're a good choice for anyone who wants to save on a mattress and get convenient delivery.