If you have a hard time keeping your emotions in check after a poor night’s sleep, research shows you’re not alone. The brain needs a certain amount of deep (or slow wave sleep) and REM sleep to repair and maintain neural pathways, including the ones that help us regulate our moods and emotions. But so few people make the connection between their mattresses and overall health until they start experiencing physical symptoms too—tossing and turning to get comfortable and waking up with sore hips and shoulders.
If you find yourself on the hunt for the best mattress—wanting the right fit that will last without breaking the bank—you may be interested in a feature called Responsive Air.
The Handbook Team testers think Responsive Air is exactly what combination sleepers need. The Sleep Number mattress senses whether you’re sleeping on your back, stomach, or side, and it fills or deflates bags of air in strategic places to reduce pressure points. It’s our favorite feature collectively, and we think it’s the true reason combination sleepers get better sleep—making the mattress worth every penny.
We test the bed at different firmness settings to help you decide whether a Sleep Number 360 i8 is right for you, even if you can’t go to a showroom to try it yourself.
Our testing experience
HelpGuide Handbook’s testing methodology and score breakdown
Our testing methodology includes a five-factor score breakdown that our hands-on product testing team uses to rate mattresses. Here’s how the Sleep Number 360 i8 mattress fares:
Pressure relief: 5/5
We believe there’s no better mattress for pressure relief than a Sleep Number because you can choose a firmer or softer setting based on how you feel. But the real magic is Responsive Air, which makes tiny adjustments to the air chambers based on where the bed senses your weight.
Many of our testers love this feature, but it’s important to pair it with the right Sleep Number setting. Responsive Air can’t do much for you if the bed is set to 100 (the firmest option), for example.
Firmness: 1/10 to 8.5/10
We evaluate the firmness of our Sleep Number mattress at levels 10, 50, and 100.
- At level 10, the mattress has a firmness score of one out of 10. It has no support and feels like the foam disappears.
- Level 50 seems like a medium-firm mattress, which has a firmness score of 6.5 out of 10.
- Level 100 feels like sleeping on a bench, but we find it cups our shoulders, hips, and legs ever so slightly. There’s a gap at our lower back, meaning we lose some lumbar support at this setting, making it an 8.5 out of 10 on our firmness rubric.
Motion isolation: 3/5
To detect motion on this mattress, we place a cup of water on the bed. We place it on one side of the bed and bounce around on the other. The water sloshes a bit, but the cup never tips over. This is an average performance.
Cooling: 2/5
We use a FLIR thermal camera (which uses infrared radiation coming from the object to capture the image) to compare the temperature of the bed where a tester had been lying versus the temperature on the unused side of the bed. There was at least a 15-degree difference, which is a poor score. For context, some mattresses show a difference of less than 5 degrees.
Edge support: 2/5
The edges of the Sleep Number 360 i8 sink quite a bit as soon as you sit on the edge of the bed. This happens no matter what firmness setting you choose. It would be easy for someone to slide off if they weren’t able to firmly plant their feet on the floor to stabilize themselves. Lying on the edge of the bed also makes our testers feel like they could easily roll off.
Sleep Number 360 i8 mattress firmness and feel
The beauty of a Sleep Number mattress is its customizable firmness. Air chambers inflate and deflate to create a firmer or softer feel, and layers of foam add another element of comfort. We test the full scope of settings to see just how soft and firm the Sleep Number 360 i8 could get.
Level five is the softest option, but the mattress doesn’t deflate past level 10. Still, this is soft enough for us to realize the mattress had lost its support. The mattress edges end up being about 4 inches higher than your body. When you sit up, you can feel a hard base layer. We wouldn’t call this comfortable, but maybe it’s exactly what you’re hoping for.
Level 100 is at the other end of the spectrum. This extra-firm setting feels rigid and unforgiving. Your body sinks slightly into the mattress at the shoulders and hips, leaving your lower back unsupported.
Sleep Number 360 i8 mattress performance
We’ve discovered a few instances where a firmer setting leads to better performance compared to what we’ve experienced on a nightly basis. For example, it’s much easier to change from your back to your stomach on a firmer setting, whereas getting out of bed is a workout when you choose the ultra-soft settings. You may also find that there’s less of a dip in the middle of the bed when both parties choose a firm setting.
That said, many features in the Sleep Number 360 i8 operate independently. Let’s take a closer look at their performance.
Sleeping position and body weight
Because the Sleep Number 360 i8 offers personalized firmness, it’s suitable for everyone regardless of sleeping position.
It can take some time to find the right setting (five to 100) for a Sleep Number mattress, but a good rule of thumb is to lie down in your usual sleeping position with the mattress set to 50. If it feels too firm, try 45 or 40. If 50 feels too soft, try 55 or 60. Keep going until you feel like the mattress makes contact with all areas of your body without creating any sore areas. Alternatively, start at five and increase until you feel your spine is in a neutral position. You’ll know whether to make more adjustments after spending a full night on the bed.
We asked Drew Miller, the vice president of marketing at independent mattress retailer Sit n Sleep, to describe the types of sleepers who benefit from firm versus soft mattresses. He recommends side sleepers choose softer settings so the mattress “follows the curves of the body and relieves pressure spots.” Back sleepers need a medium-firm setting (Sleep Number 50) or higher “to maintain the spine’s natural curve and keep the lower back from sinking.”
“[For stomach sleepers,] a firm mattress is necessary to maintain spinal alignment and avoid excessive hip sinking, which puts undue strain on the lower back,” Miller says. The great thing about a Sleep Number bed is you can try any level of firmness to find what suits you best. If you primarily shift between your stomach and back, you likely need a firm setting of 60 or higher. In reality, you may feel the best pressure relief at a soft 30.
In terms of the bed’s weight capacity, it depends on the size of the mattress. We couldn’t find this information on the Sleep Number website, so we asked customer service. They said mattresses queen-size and smaller can support up to 400 pounds per side, whereas king-size Sleep Number mattresses can support up to 600 pounds per side.
Sleep Number 360 i8 mattress pain relief performance
We think the Sleep Number 360 i8 is excellent for pain relief. We’ve been able to find a setting that provides a good balance of comfort and support, and the Responsive Air feature makes minor adjustments that will put your body in a more neutral position depending on how you’re lying. One of our testers says she’s less likely to wake up with sore, stiff muscles since buying this mattress, especially around her hips, shoulders, and neck.
Sleep Number 360 i8 mattress cooling performance
Sleep Number claims the Innovation series mattresses have advanced temperature-balancing materials. The idea is that a ceramic gel inside the mattress pulls heat away from your body so you sleep cooler. We put that to the test by measuring used and unused spaces on the mattress with a thermal camera. The camera measured a 15- to 21-degree difference, which suggests poor cooling mechanisms in the fabric and foam.
One tester notes she tends to run hot at night and often has to throw off the blanket to get comfortable. She didn’t feel like the mattress itself caused her to overheat, but it could have contributed to the problem.
Sleep Number 360 i8 mattress for couples
Sleep Number mattresses may be perfect for couples who need different firmness settings. All Sleep Number mattresses queen-size or larger, regardless of the model, have two independent air chambers on each side of the bed.
You can apply these settings to your side of the 360 i8 without disturbing a partner:
- Firmness.
- Responsive Air.
- Under-bed lighting (requires Sleep Number’s FlexFit adjustable frame).
- Head positions (requires FlexFit frame and a split top or full split mattress).
- Feet positions (requires FlexFit frame and a full split mattress).
In our experience, Responsive Air seems to connect to the entire bed. When it’s turned off on one side, it gets turned off on the other side too. The same thing happens with some adjustable base settings, like zero gravity. This is a glitch we haven’t worried about troubleshooting because we all like to use Responsive Air, but we’d encourage you to make sure all settings work independently before the setup crew leaves.
Another issue couples may want to look out for is the so-called trench effect, which refers to a dip that can appear between the two sides of a Sleep Number mattress. If you move around a lot at night and often end up rolling into this valley, you can crowd a partner. This may happen more often with lower firmness levels, which soften to create a valley wherever you rest.
Sleep Number 360 i8 sex score
Some people look for a mattress that’s good for sex as well as sleep, but Sleep Number models seem to be designed for one purpose only: rest and relaxation.
There’s no bounce, the edge starts to slowly sink once you put weight on it, and you’ll fight the material when moving around, depending on the firmness setting and whether Responsive Air is turned on.
Sleep Number 360 i8 app features
The Sleep Number 360 i8 is a smart bed, so it connects to an app through Wi-Fi or Bluetooth. The app lets you control features on the bed and base (if applicable). You can also buy a remote control, which is especially helpful if you consider the bedroom a screen-free zone.
We were surprised by how many health- and sleep-tracking features we found on the Sleep Number app. The bed uses special sensors to measure heart rate, heart rate variability, and breath rate while you sleep, and it tracks your averages on a nifty graph. It also records how often you get out of bed in the middle of the night, how long it takes you to fall asleep, and how much time you spend in a restless state.
All of this information is compiled into a nightly SleepIQ score, which gives you a rough estimate of your sleep quality. The app also analyzes your data and suggests ways to improve your sleep score and maximize your day. Although SleepIQ isn’t a diagnostic tool, one study found it “moderately to strongly accurate” when compared to data from other sensors. We think it’s interesting to see trends over time, and we appreciate that we don’t have to wear extra trackers to collect this data.
Setting up and moving Sleep Number mattresses
When you buy a Sleep Number mattress, you’ll be charged an extra fee ($250) for delivery and setup. This is not optional, and even if it were, we wouldn’t recommend skipping it. Sleep Number mattresses are heavy and difficult to move, so make sure you’ll be happy with where the bed is set up. Learn from one tester’s mistakes, and don’t block access to important electrical plugs—you won’t be able to scoot the bed out of the way to reach them.
Set up takes about 10 minutes. Sleep Number asks that you already have the old mattress out of the way and the headboard and bed frame set up. The technicians need your home Wi-Fi password, but other than that, you can step aside and let them do the hard work.
Our final thoughts about the Sleep Number 360 i8
We think the Sleep Number 360 i8 is a great investment. When you aren’t sure what kind of firmness you need, buying a new mattress can feel like a gamble. Sleep Number eliminates that worry with customizable firmness and a smart airbed system that gives personalized pressure relief. If you need different levels of support in the future, you can just tap a button instead of buying a brand-new bed.
We’re drawn to the thick, supportive foam and pillow top on the Innovation series, but if that’s not important to you, you can save some money by choosing from the Classic or Performance series.
If you’re concerned about the price of a Sleep Number mattress, here are some final tips to help you lower the cost.
- Ask around to find someone who already owns a Sleep Number. They can log into their account and share their Refer-a-Friend link to give you 20 percent off.
- Wait for a sale. Some Sleep Number mattresses cost more than $7,000 at retail price. They go on sale throughout the year (especially around holidays), allowing you to save a significant amount of money.
- Ask about financing. For example, you may qualify for 36 months of zero-interest financing but may get a different offer based on your credit score.
Frequently asked questions about the Sleep Number mattress
Sleep Number claims its mattresses are designed to last at least 15 years. As such, they’re covered under a 15-year warranty.
A Sleep Number mattress is for anyone, but it’s especially useful for couples who want to customize the firmness of their side of the bed.
No, Sleep Number mattresses don’t need a box spring, and the company actually recommends against using one. A firm, solid surface, such as bed slats, plywood, or a Sleep Number base, is preferred.
References
- Medic, G., Wille, M., and Hemels, M. E. (2017). Short- and long-term health consequences of sleep disruption. Nature and Science of Sleep, 9, 151–161. https://doi.org/10.2147/NSS.S134864
- Scott, A.J., Webb, T.L., Martyn-St James, M., Rowse, G., & Weich, S. (2021). Improving sleep quality leads to better mental health: A meta-analysis of randomised controlled trials. Sleep Medicine Reviews, 60, 101556. https://www.sciencedirect.com/science/article/pii/S1087079221001416?via%3Dihub
- Siyahjani, F., Molina, G. G., Barr, S., and Mushtaq, F. (2022). Performance evaluation of a smart bed technology against polysomnography. Sensors (Basel, Switzerland), 22(7). https://doi.org/10.3390/s22072605
- Vandekerckhove, M. (2018). Emotion, emotion regulation and sleep: An intimate relationship. AIMS Neuroscience, 5(1), 1–17. https://www.aimspress.com/article/10.3934/Neuroscience.2018.1.1