Sleep Number 360 i8 Smart Bed Review (2024)

Changing your mattress can be a nerve-wracking experience. Without actually sleeping on it, it's hard to know whether it will be too hard, too soft, or hurt your back. Sleep Number's 360 Smart Beds are expensive, but eliminate those worries with a companion app that lets you easily adjust the mattress from ultra-soft to extra-firm, or anywhere in between. Since we last reviewed a Sleep Number 360 Smart Bed in 2018, the company has added new health and wellness features and revamped its SleepIQ app, compelling us to revisit the product.

The 360 i8 Smart Bed (and FlexFit 3 base) we tested this time around offers the same core features for which Sleep Number is known—adjustability on both sides for different sleepers, automatice firmess adjustments, and sleep tracking—with a temperature-balancing surface that keeps you cool, and a base that can elevate your feet to improve circulation and warm them to help you drift off faster. Priced at $3,799 for the queen size mattress we tested (plus another $2,399 for the base), it's a sizable investment, but if you're in search of a comfortable, customizable bed to monitor and improve your shut eye, the Sleep Number 360 i8 earns our Editors' Choice award.

Bed Types, Bases, and Pricing

Sleep Number sells several different 360 Smart Beds, with queen sizes starting at $1,099 for the entry-level c2 Classic series model. The company offers its FlexFit adjustable bases(Opens in a new window) starting at $1,499 for a queen.

The mattresses come in a range of industry-standard sizes(Opens in a new window) that fit into traditional frames and furniture sets: twin (38 inches wide by 75 inches long), twin XL (38 by 80 inches), full (54 by 75 inches), queen (60 by 80 inches), king (76 by 80 inches), and California king (72 by 84 inches).

All 360 Smart Beds feature DualAir adjustability, Responsive Air technology, and Sleep IQ tracking. The DualAir feature allows you to dial the firmness of each side independently, so if you like sleeping on a cloud and your partner prefers a brick, you can both have it your way. The Responsive Air feature monitors the bed's air pressure level as you sleep, and automatically adjusts to maintain your desired firmness. The SleepIQ feature tracks your shut eye, heart rate, breathing, and more.

All three above-mentioned features are optional; if you're a solo sleeper, you can get a single-chamber mattress you adjust all at once. (There is no price difference between Sleep Number's single- and dual-chamber mattresses, however.) If you're not a fan of the Responsive Air or sleep tracking features, you can easily disable them in the app.

The last time we reviewed a Sleep Number 360 Smart Bed, we tested the p5 Performance series model with a FlexFit 1 base, which is still on the market. A Sleep Number spokesperson tells me that the p5 is a popular model, and the company recently updated it with a new sleep surface for improved pressure relief.

For this review, Sleep Number sent me a queen size i8 mattress ($3,799) from its top-of-the-line Innovation series, along with its most advanced adjustable base, the FlexFit 3 ($2,399). To go with the bed, Sleep Number sent a queen-size True Temp sheet set ($209.99 for one flat sheet, one fitted sheet, and two pillowcases) and a True Temp Classic pillow(Opens in a new window) ($109.99). Including the $199 home delivery and setup fee, this entire setup costs $6,716.98 before taxes.

The Innovation series offers all the perks of the lower-end models, but with a temperature-balancing sleep surface that absorbs excess heat, then releases it as you cool down. The surface is made of "smart 3D fabric," which Sleep Number claims is 50% more breathable compared with standard mattresses.

Sleep Number currently offers two different FlexFit bases, both of which can raise your head and feet, and support app control. The top-tier FlexFit 3 can also warm your feet to help you drift off, and features an optional motion-sensing underbed light (one of my favorite features) to illuminate your way during late-night bathroom runs.

Selecting a Bed and Preparing for Delivery

If you're seriously considering getting a 360 Smart Bed, I strongly suggest speaking with one of the company's Sleep Professionals, who can assess your needs, give you a rundown of the different models and features, and help you pick the best model for you.

Sleep Number's beds are expensive, but the company often runs promotions, so wait for a deal if you can. At the time of this writing, it's offering $800 off 360 Smart Beds as part of a fall sale. The company also occasionally waives its $199 premium delivery and setup fee, which is otherwise required with the purchase of any 360 Smart Bed.

To make the cost more manageable, Sleep Number offers financing options through Synchrony Financial starting at $45 per month. For peace of mind, the company also offers a 100-night trial(Opens in a new window) and a 15-year limited warranty(Opens in a new window).

Before receiving my review unit, I was a little nervous about whether it would work with my current bed frame, and I'm happy to report that it does. The FlexFit base needs to sit directly on the floor, but in many cases, can be dropped into your existing bed frame, as is the case with my setup. Sleep Number says it won't work with platform furniture and frames with under-bed storage.

To determine if it will fit, you need to measure the inside of your existing bed frame and compare its dimensions with that of the FlexFit base. For instance, the queen FlexFit base measures 58.5 inches wide by 79.5 inches long. As long as your existing frame is larger than the base, it should work. Sleep Number has detailed instructions(Opens in a new window) on measuring your existing furniture to ensure it offers enough space for a FlexFit base.

After placing your order, the company will email you with your delivery date, but you can always call to reschedule if necessary. Before the bed arrives, be sure to prep your space, download the SleepIQ app (available for Android and iOS), and have your order number handy (it should be in every delivery email from the company). On the day of your delivery, Sleep Number's team will carry in your new bed, set it up, and help you pair it with the app. A spokesperson tells me that the home delivery team can haul away an old mattress and box spring, but they can't physically move or alter your existing furniture.

The bottom of the base (Photo: Angela Moscaritolo)

In my experience, the delivery and setup process couldn't have gone any better. The day after Sleep Number placed my order, I got an email with my delivery date, about two weeks out. Two days before my delivery, the company sent another email with a four-hour delivery window when I could expect them to arrive. On delivery day, the team arrived on time, wearing masks as a COVID-19 precaution, and took about an hour to set up the bed, if that. I was able to use my existing bed skirt, but they had to cut a small hole in it for the bed's wires. This didn't bother me, because the hole is hidden under the mattress.

To register a new account in the SleepIQ app, you just need to enter your email address and order number. From there, the app asks you to name your bed, input some information about yourself (your birth year, height, weight, gender, and time zone), and set up a sleep goal. The app then scans for nearby Wi-Fi networks to connect your bed; just click your network, enter your password, wait for it to connect, and you should be good to go.

Controlling Your Bed and Finding Your Sleep Number

The SleepIQ app is well organized and easy to navigate, with three tabs on the bottom: Sleep, Bed, and Profile.

In the Bed tab, you can adjust your Sleep Number setting, control the FlexFit base, and set up bedtime Routines so the foot warmer is on when you tuck in at night. Here, you can also enable/disable the Responsive Air, underbed lighting, and sleep tracking features.

Your Sleep Number can range from 5 (the softest setting) to 100 (the firmest), and is adjustable in increments of 5. The SleepIQ app offers a useful feature that can help you find your ideal setting, though it still takes some trial and error. Navigate to Bed > Sleep Number Setting > Find Favorite, and the app will let you test a range of firmness levels.

Since it can take some time to get used to a new mattress, Sleep Number recommends trying your selected firmness setting for two to five nights. If you're not comfortable, try adjusting it by 5 or 10. Increasing the number will increase the firmness, and vice versa. I like my mattress on the softer side, so I kept my Sleep Number at 30 for the first few nights. That was a little too soft, so I increased it to 45, which feels perfect.

Adjusting your Sleep Number can help alleviate back pain, soreness from working out, and other issues.For lower back pain, the company recommends lowering your Sleep Number by 5 or 10, to make the bed softer, for three to six nights. It also might help to lower your Sleep Number after a hard workout, when you're sick, or if you're pregnant. For middle or upper back pain, or increased hip support, the company recommends increasing your normal Sleep Number setting, to make the bed firmer.

The SleepIQ app offers a few presets that let you adjust the FlexFit 3 base with a single tap, including Flat, Zero G (which raises both your head and feet), and Snore (which raises just your head). Arrow buttons in the app let you manually raise and lower your head and feet to your desired level, and you can save your favorite position as a custom preset. With the head of the bed fully raised, you're sitting upright, almost like you would on a couch. A Sleep Number spokesperson says the Zero G position is good for relieving pressure in your back. The app also lets you set a timer for the bed to automatically adjust to a different position after anywhere from 15 minutes to 3 hours.

If you're a light sleeper, you might not love the Responsive Air and underbed lighting features. With Responsive Air enabled, the bed will take pressure readings once per hour throughout the night to sense changes due to temperature and movement, then automatically adjust the firmness level to maintain your preferred Sleep Number setting. If you have a dual-chamber mattress, it will make adjustments for each side. You can very faintly hear the bed adjusting, so if you're easily awakened, you might want to keep this feature off (it's disabled by default). I have it enabled, and it doesn't bother me.

The underbed light is set to auto by default, but you can disable it if you prefer. When you get out of bed, it automatically turns on to softly illuminate the floor. When you get back into bed, it automatically turns off. If you don't get back into bed, it automatically turns off after 10 minutes. The app also lets you turn the underbed light on and off at any time, set the brightness level (low, medium, or high), and set a timer for it to automatically turn off after 15 minutes to 3 hours.

Keeps Your Feet Warm and Your Body Cool

If you're always cold, you're probably going to want the FlexFit 3 for its signature foot-warming feature, which isn't available on the company's other adjustable bases. As its name suggests, this feature warms just the foot end of the bed. It takes around 15 to 30 minutes to heat up. "Research has shown that having your feet gently warmed may help you fall asleep faster," Sleep Number says.

With a dual-chamber mattress, you can individually control this feature on each side, so one person can have the foot warmer turned on and the other can have it turned off.

In testing, this feature has worked wonderfully. I have it set to High, and it gets toasty but not too hot. My one gripe is that you can only enable this feature as part of a Routine in the SleepIQ app. And since it's only available in the Routines section of the Bed tab, it's a bit hard to find.

To enable it, navigate to Bed > View Routines > Create a New Schedule. From there, you can select certain days of the week, set your bedtime, and set the foot warming temperature (off, low, medium, or high). After creating your Routine, the foot warmer will turn on 30 minutes before your bedtime, so it's ready when you hop in. As you fall asleep, it will automatically cool down.

If you want to turn it on outside of your normal bedtime, you have to create a new Routine, which is sort of a hassle. I wish there was a button in the app to let you turn it on and off whenever you want.

Sleep Number makes a handheld remote control (sold separately) that, among other features, lets you turn the foot warmer on and off at will. At the time of this writing, however, the remote is off the market due to supply chain issues, and a Sleep Number spokesperson couldn't share an availability date. The remote also lets you set the warming temperature, and a timer for 15 minutes up to 6 hours. If you turn it on with the remote but don't set a timer, it will automatically turn off after 2 hours.

While the FlexFit 3 keeps your feet warm, the i8 keeps your body cool. Its breathable, temperature-balancing sleep surface makes it an excellent option for those who run hot. Paired with the True Temp sheets, the bed offers a cool, crisp feeling when you get in, even with the foot warmer on.

The fitted True Temp sheet has elastic bands on each corner that prevent it from sliding off, a small but welcome feature. I've had the same pillow for as long as I can remember, so I was a bit worried I'd have a problem getting used to Sleep Number's True Temp Classic, but I really like it. I have zero complaints about the comfort of this setup.

Tracking Your Sleep

Given the affordability of sleep tracking wearables such as the $179.95 Fitbit Charge 5, I wouldn't necessarily buy a Sleep Number 360 Smart Bed just for its ability to monitor your shut eye. That said, its insights about your slumber are a nice perk, especially if you find it too uncomfortable to wear a fitness tracker or smartwatch to bed.

It automatically tracks the total amount of time you spent in bed, how long it took you to doze off, what time you fell asleep and woke up, and the duration of bed exits. It doesn't track your light, deep, and REM sleep stages, like most fitness trackers, but it will tell you the duration of your restful and restless sleep the previous night, and keep a record of your all time-averages for these metrics. After tracking your rest, the app gives you a SleepIQ score from 5 to 100 to help you quickly gauge the quality of your shut eye.

While you sleep, it also tracks your heart rate, heart rate variability (HRV, or the amount of time between successive heart beats, a measure of your nervous system activity and stress level), and breath rate (also known as respiration rate, or the the average number of breaths you take per minute). The SleepIQ app clearly explains these metrics and tells you why they're important, to help you make sense of your data.

"High HRV means high energy, good recovery, enhanced cognitive performance, and balance of heart and mind," the app says. "Low HRV means low energy, low immune system, high stress, and imbalance of heart and mind."

The app also keeps a record of your averages, and displays 7- and 30-day trend graphs for each metric, so you can quickly compare your results from the previous night to your baseline. It delivers monthly wellness reports to help you track your sleep over time, and helpful tips to help improve it.

The app recommends adjusting your Sleep Number setting once a week, noting that users who do "get more restful sleep each night" compared with those who don't.Over the past month, it has also urged me to reduce blue light exposure before bed to help improve my HRV and sleep quality.

In testing, the i8 has accurately tracked my sleep duration and breathing rate when compared with the $99 Google Nest Hub smart display, which monitors your sleep and respiration from your nighstand. For the same night, the SleepIQ app said I spent 7 hours, 3 minutes sleeping while the Nest Hub logged 7 hours, 6 minutes of sleep time. The SleepIQ app said I had a breath rate of 15, to the Nest Hub's 14 respirations per minute.

I find that the 360 Smart Bed sometimes classifies time spent in bed on my phone as "restless" sleep, which isn't totally accurate, but this is a small gripe. On the plus side, its sleep monitoring feature is so sensitive, I've found that it even tracks quick naps.

A Smarter Night's Sleep

The Sleep Number 360 i8 Smart Bed keeps your body cool thanks to its temperature-balancing sleep surface, while the FlexFit 3 base warms your feet with a built-in heater. Its excellent SleepIQ companion app allows for truly customizable comfort, letting you adjust the firmness and the position of the mattress to suit your preferences. It tracks your sleep health and biometrics, and offers useful tips to help improve your shut eye. Priced at $6,198 for the mattress and base configuration we tested, it will put a dent in your bank account, but a good night's rest is crucial for health, and the Sleep Number i8 makes every night a dream, earning it our Editors' Choice award.

If a Sleep Number is out of your budget, however, the Eight Sleep Pod Pro Mattress(Opens in a new window) ($3,095 for a queen) looks to be a promising alternative. It isn't adjustable like a Sleep Number, but it tracks similar sleep and health metrics, supports dual-zone heating and cooling, and can vibrate to wake you up without disturbing your partner. We haven't tested it yet, but an older Eght Sleep model scored well, and at half the price of the Sleep Number, it's worth a look.