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As Insider's mattress reviewer, I don't get to sleep on the same bed every night. But if I could stick with one bed, I would choose a Sleep Number. Sleep Number is the top name in adjustable air mattresses thanks to its high-end service and innovation. This is evident in the 360 i8 mattress, the top adjustable bed pick in our best mattress guide.
All Sleep Number beds have 20 mattress firmness options. The 360 i8 innovates on this with the sleep-tracking SleepIQ app and responsive air that adjusts the firmness for consistent comfort as you shift in the night. This feature might sound gimmicky, but it helps me stay asleep.
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These are the Sleep Number 360 i8 Smart Bed specs at a glance:
Sleep Number 360 i8 Smart Bed | Specifications |
Best for: | All sleeping styles, couples |
Available sizes: | Twin XL, full, queen, king, split king, flextop king, California king, split California king, flextop California king |
Mattress type: | Adjustable air |
Firmness (1 softest to 10 firmest): | 20 firmness levels |
Motion isolation (1 awful to 10 best): | 3 |
Heat dissipation (1 traps heat to 10 stays cool): | 3 |
Edge support (1 awful to 10 best): | 6 |
Trial period/warranty: | 100 nights; 15 years |
Weight/thickness: | 80 pounds; 12 inches |
Shipping and returns: | Free shipping but return shipping fees apply |
White-glove delivery and mattress removal: | Free with purchase of mattress and base |
Showroom availability: | Yes, nationwide |
Setup
In-home setup by the Sleep Number delivery crew is included with the mattress purchase. I like that they don't rely on third parties for this service because you know you're getting people who know what they're doing.
This proved true when the delivery people couldn't get the queen bed frame up my tight staircase. They recommended a split king frame, which comes in two pieces. This pushed the delivery date back a month. If you're unsure about what bed size you need, check out our mattress size chart.
The second try was successful. The workers set up the base and mattress in about 45 minutes, ensuring my phone was paired with the bed and showing me how to use the app. Despite the brutal task of carrying the components to my third-floor bedroom, they were professional and helpful.
Though the bed had a strong new bed smell, the odor dissipated by bedtime.
Review of the Sleep Number 360 i8 Smart Bed
I'm a side sleeper but spend time in every sleeping position. Using the SleepIQ app (available for iOS and Android), you can turn on the "responsive air" function, which automatically adjusts the firmness as you change positions. This gives you consistent comfort and pressure relief. It worked seamlessly and did a good job of facilitating restful, undisturbed sleep.
The Sleep Number 360 i8 Smart Bed uses ballistocardiography, a measure of ballistic forces coming from your heart, to calculate your sleep quality and provide a sleep score. After you track your sleep for several weeks and input your sleep goals, the app offers tips for more productive sleep.
In the six months my wife and I tested the bed, Sleep Number made several tweaks to the app that have improved the sleep-tracking accuracy. I checked for accuracy by comparing the data to my Garmin Forerunner 945 smartwatch readings and my subjective experience.
Sleep Number is best known for its adjustable firmness. The mattress has 20 firmness levels. Your "sleep number" is your preferred firmness level from 5 (softest) to 100 (firmest). My sleep number was 35, but my wife preferred 55. Fortunately, the two sides are individually adjustable so couples with vastly different preferences can be comfortable.
Finding the right firmness was easy. Sleep Number recommends lying in your preferred sleep position and starting at 100. Then, slowly decrease the firmness using the SleepIQ app until you're comfortable. Finding my sweet spot took me a few nights of trial and error, but I didn't make additional adjustments.
I was impressed with the edge support of the mattress. I felt comfortable sitting on the side of the bed to put my socks and shoes on and when I laid on the edge to cuddle my wife in the morning.
I love how few wires the 360 i8 smart bed has. The adjustable base (I tested the FlexFit 2) and mattress are powered by one electrical cord that plugs into your wall. This starkly contrasts with the other adjustable beds I've tested, which leave several wires on the floor and require multiple wall outlets.
I also appreciated that I didn't need a remote to operate the mattress. The app controls everything. When I made adjustments, it was whisper-quiet.
Cons to consider
The motion isolation of the Sleep Number 360 i8 was subpar. My wife said it felt like a waterbed when I flopped on the mattress.
The heat dissipation was also poor. When I got up to go to the bathroom at night, the spot where I was sleeping would still be warm when I returned. Hot sleepers may want to consider another option. I'd recommend the Sleep Number Climate360 if you can afford the $10,000 price tag. I'm currently testing this and am impressed with its built-in heating and cooling capabilities, giving you a custom feel. It may be the best cooling mattress I've tested.
As I tested mattresses on the other side of our "bedrooms," my wife continued to sleep on the 360 i8 for several months. She liked to sprawl out. Unfortunately, the divider between the two air chambers makes sprawling uncomfortable. Also, the sleep tracker didn't recognize when one person was sprawled across both sides of the bed. Consequently, her sleep stats were inaccurate when she did this. For these reasons, I would not recommend Sleep Number beds for people who sleep alone.
The mattress is also hard to move since it is attached to the base. You can try to detach it and move it separately or attempt to move the whole unit. Either way, it's a chore.
Should you buy it?
At $4,000 for the queen, the Sleep Number 360 i8 is out of the price range of most consumers, even if it does come with a basic foundation and white-glove delivery. But it's worth it if you can afford it, especially considering a 15-year warranty covers it. Sleep Number also offers financing options starting at $49 per month.
Your mattress preferences change over time. I was 50 pounds heavier two years ago and preferred a firmer mattress. Now, I look for something softer to keep my spine aligned as I sink in less. If this happens and you have a non-adjustable mattress, you either need a new mattress, a mattress topper (see our best mattress topper guide), or live with being uncomfortable. With a Sleep Number, you choose a new firmness.
I recommend the Sleep Number to older couples since comfort preferences are more refined as you age.
The bottom line
If I weren't a mattress tester trying out new beds every two weeks, I would sleep on a Sleep Number Smart Bed every night. Even though I sleep hot and the Sleep Number 360 i8 tends to retain heat, I recommend it because of the responsive air feature that keeps my comfort consistent no matter my position. As a stats person, I like as much sleep tracking info as possible to achieve better, more restful sleep. I strongly recommend the Sleep Number 360 i8 Smart Bed if you can afford it.
Pros: Responsive air adjustments provide consistent comfort and support, built-in sleep tracker with sleep tips, good edge support, white-glove delivery included with purchase, 20 firmness options independently adjustable on each side, great for couples
Cons: Retains heat, poor motion dampening, hard to move, not ideal for people who sleep alone
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Senior Reporter, Insider Reviews
James is a Senior Reporter for Insider Reviews, specializing in sleep, HVAC, vacuums, and kitchen appliances. He has tested more than 70 mattresses from startups like Casper and legacy brands like Tempur-Pedic, using his background in experimental psychology to develop objective tests and evaluate comfort, support, motion transfer, and more. He authors our guide to the best mattresses. In addition to being Insider Reviews' mattress expert, James has extensively covered vacuums, air conditioners, air purifiers, and more within the HVAC space. He's tested more than 40 vacuums from brands like iRobot and Dyson and is no stranger to keeping his house at a chilly 60 degrees Fahrenheit for weeks on end, all in the name of testing air conditioners. He's a multifaceted writer who has covered everything from health and fitness to consumer technology. His mission is to help people get the most value for their money by guiding them in making informed buying decisions. James lives in Lansing, Michigan with his wife, two kids, a tabby cat, and a rambunctious rat terrier.When James isn't testing products and writing for Insider, he helps run a popular local Facebook group, Lansing Foodies, and plans the Olive Burger Festival. See below for some of his work:
- The 16 best mattresses for a good night's sleep, tested and reviewed by sleep experts
- The 7 best vacuum cleaners for every type of mess, budget, and floor type
- Travel guru Rick Steves never checks a bag. Here are the 25 things he always packs in his carry-on.
- I toured 8 distilleries on the Kentucky Bourbon Trail – here are the 16 best whiskeys I tried and where to buy them
- The 10 best bourbons we recommend after tasting over 100 bourbon whiskeys and talking with experts
- The 6 best air fryers that are actually worth the counter space
Contact info: jbrains@insider.com Learn more about how our team of experts tests and reviews products at Insider here. Learn more about how we test kitchen products.