Sleep Number Mattress Review

In This Review
Performance Tests | Firmness | Support & Sleeping Positions | Design | Materials | Comparisons | FAQs

Testing Notes

This is a well-used mattress that was used as a primary mattress for 5 years before migrating to a guest room. This mattress is owned by friends of the NapLab (hence the different pictures).

It was manufactured in 2014. According to the law tag, it’s model 1357, but I wasn’t able to match that to any type of normal mattress series name.

Based on the year it was made, the remote, and the material design I am reasonable confident that this is a Sleep Number Classic Series, model C2.

However, Sleep Number’s website documentation for older models is severely lacking, so I am not 100% certain.

At NapLab, we put each mattress to the test.

We test 10 different factors that impact the performance, comfort, and value of the mattress. We then take the results of that test and compare to every mattress we’ve tested to date.

Check out the full performance table below to see how this mattress ranks:

Factor	Sleep Number C2	Average
Overall Score	8.04	8.57
Price (Queen)	$1,099	$2,275 (Adjustable only)
Cooling – Score	9.0	8.7
Sinkage – Depth	2.35″	2.14″
Sinkage – Feel	Deep	Moderate
Motion Transfer – Score	6.8	8.2
Motion Transfer – Acceleration	12.10 m/s²	8.78 m/s²
Response Time – Score	9.7	8.9
Response Time – Mostly Recovered	0.2 sec.	0.4 sec.
Response Time – Fully Recovered	0.6 sec.	0.9 sec.
Bounce – Height	11.66″	9.54″
Bounce – Feel	High	Moderate
Edge Support – Score	7.4	8.6
Edge Support – Sitting	4.00″	4.03″
Edge Support – Lying	Mediocre	Good
Sex – Score	9.4	8.5
Pressure Relief – Score	8.0	8.7
Comfort Layer Thickness	3.5″	4.1″
Mattress Thickness	9.5″	12.0″
Off-Gassing – Score	7.2	8.1
Off-Gassing – Smell	Strong	Strong
Off-Gassing – Days	10 days	7 days
Company – Score	6.1	8.7
Trial	100 nights	178 nights
Warranty	15 years	25% have lifetime warranties, average of other 75% of mattresses is 13 years

How is Sleep Number Different?

The Sleep Number C2 mattress has lower performance than average, and average price (considering adjustable mattresses only within the C2 model).

Advantages

In our performance test, the C2 has slightly better cooling than average, as well as faster response time, slightly better edge support, and better sex performance.

Neutral Factors

Considering preferential factors, the Sleep Number C2 has widely variable sinkage levels and 20% more bounce than the average level.

Disadvantages

But the mattress also has 51% higher levels of motion transfer, 15% less comfort material, and is 21% thinner than the average mattress (comparing over 170+ mattresses tested to date).

Cooling performance on the Sleep Number C2 was excellent. During our tests, I felt no significant level of heat retention.

The Sleep Number’s design is beneficial for cooling as there is very little material that can actually absorb and hold onto heat.

The mattress is 3.5” of foam on top of a 6.0” adjustable rubber bladder. Being adjustable, the rubber bladder is filled with air, which won’t retain heat the same way that a foam support layer will.

• Baseline Temperature – the temperature of the mattress before anyone lies on it
• Maximum Temperature (0 minute) – the temperature of the mattress after lying on it for 15 minutes
• Ending Temperature (5 minute) – the temperature of the mattress after being lied upon and having no one on it for 5 minutes

While the 3.5” foam comfort layer isn’t a miracle worker for pressure relief (which we’ll discuss below), the limited thickness does help to keep cooling in check.

In our objective cooling tests, we measured a max surface level temperature of 88.0° F. After getting off the mattress, we measured a decline of 0.7° from minutes 0 to 1 and a decline of 3.7° from minutes 0 to 5.

This specific mattress (owned by a friend of NapLab) is located in a cooler part of Arizona compared to our normal testing studio.

Heat Dissipation Over Time

As a result, the objective temperature measurements compared to the rest of our testing data aren’t as easily compared. Even so, given the basic material design, I am confident that most sleepers will still find this mattress perfectly fine with respect to cooling performance.

The Sleep Number has a varying level of sinkage based on the Sleep Number level.

The lower the number, the more sinkage and the softer the feel. The higher the number, the less sinkage and the firmer the feel.

In our tests, the sinkage depth varied from a moderate level of sinkage all the way up to extremely deep.

In the table below, select a specific firmness to see the associated sinkage.

Considering the wide range, I wasn’t surprised to see a deep sinkage for the lower numbers. However, I was surprised to see more moderate sinkage for the highest numbers (especially 70-100).

At these sleep numbers, there is a high degree of floating feel on the mattress. This is in contrast to the sinkage depth. What’s happening here is simply that the topmost 3.5” layer of foam is extremely soft.

As a result, it creates very little pushback or resistance, allowing even an object as light as a 12-pound medicine ball to sink through the majority of its 3.5” layer.

The Sleep Number mattress has a high level of motion transfer. In our tests, we measured a total acceleration range of 12.10 m/s². This is 3.32 m/s² more motion than the average of 8.78 m/s².

The level of motion was not surprising. At the end of the day, this is a rubber air bladder. Air and rubber create a high degree of bounce and also a high degree of motion.

The level of motion transfer is also documented in the video below.

Just like the air in basketball, football, or soccer ball, the air-filled rubber of Sleep Number highly rebounds energy.

Looking at our motion transfer chart, which visualizes our accelerometer data, we see the highest motion from 0 to 0.14 seconds.

Motion declines thereafter, but we see a notable secondary energy spike from 0.49 to 0.63 seconds. It isn’t until 1.20 seconds that we return to near-zero levels of motion. The motion duration, motion intensity, and secondary spike all tell the same story, Sleep Number has a high level of motion transfer.

The Sleep Number C2 has a very fast response time. In our tests, we measured a mostly recovered response time of 0.2 seconds and a fully recovered response time of 0.6 seconds.

Both of these were notably faster than the average response speed of 0.41 (mostly recovered) and 0.9 (fully recovered).

The level of responsiveness is documented in the video below.

The limited foam layer on top, use of poly foam instead of memory foam, and rubber bladder all work together to deliver higher responsiveness.

The faster response helps to prevent any type of a stuck feeling and improves ease of movement on the mattress.

The Sleep Number C2 has a very high level of bounce. In our tests, we measured a total bounce height of 11.66”. This is 2.12” more bounce than the average of 9.54”.

The level of bounce is also documented in the video below.

As with motion transfer, the high bounce is a result of the rubber air bladder. Such a design choice creates a high energy rebound, especially in moderate to higher sleep number firmness levels. The higher bounce, while a detriment to motion transfer, does improve sex and ease of movement.

The Sleep Number has mixed edge support. Sitting edge support is good, however, lying edge support left much to be desired.

In our sitting edge support tests, we measured a sitting sinkage depth of 4.0”. This is 0.03” less sitting sinkage compression than the average of 4.03”.

Sleep Number does use a perimeter edge support foam, which is absolutely helping the sitting sinkage compression. Even when sitting directly on the edge, I felt well-supported.

The level of edge support while seated is documented in the images below.

That said, lying edge support just wasn’t great. When lying directly on the edge I did not feel well supported in any sleeping position. The problem is that the sleep support for Sleep Number comes from the adjustable air bladder.

This bladder must be contained by the perimeter edge support foam, which means when you are lying closer to the edge you are no longer lying in the center of the adjustable bladder. The result is a less-than-great level of support when lying near the edge.

The level of edge support while lying is documented in the images below.

If you sleep near the edge or middle of your mattress (in a Queen or King setup) I would advise caution when considering Sleep Number for this reason. The optimal support for Sleep Number is always going to be with your body directly over the adjustable air bladder.

The Sleep Number C2 has excellent sex performance. On the positive side, bounce is very high at 11.66″, which is 2.15″ more than the average bounce height of 9.51″.

It also has good sitting edge support. And because it is adjustable, you can turn the number up to 100 for maximum bounce and pushback when you know you need it.

The rubber bladder does generate a bit of noise and pressure relief isn’t amazing, but neither of these two factors hurt the sex score too much. Overall, the Sleep Number gets a great score for sex.

Sex Factor	Factor Weight	Score	Rating
Bounce	65%	9.8	Very High
Edge Support	20%	8.8	Good
Noise	5%	8.0	Moderate
Pressure Relief	5%	8.0	Good
Cooling	5%	9.0	Excellent

Pressure relief on the Sleep Number is good, but far from great. In our tests, I felt a slight to moderate level of pressure point build-up.

The mattress has a fairly limited 3.5” comfort layer. Normally, a 3.5” layer would be sufficient. However, the foam quality and general resiliency of the foams really left me disappointed.

The foams are extremely soft and don’t create much of a barrier between sleepers and the adjustable rubber bladder. The result is that the body ends up significantly engaging with the support system (rubber bladder) far more so than would be the case on many other mattresses we’ve tested.

The rubber bladder itself isn’t very comfortable. Which makes sense, as it’s a support layer. But the fact also means it’s not great at creating pressure relief. Notably, this is an older Sleep Number and among their more budget-friendly lines.

So it’s possible (and likely) that newer and more expensive Sleep Numbers would perform better in this area. Even so, I suspect this is a design issue that even higher-end adjustable mattresses will struggle with.

Off-gassing performance on the Sleep Number was strong when originally purchased and according to the owner, the odor lasted for 10 days.

Comparing this to the results of all mattresses tested to date, the Sleep Number off-gasses a little slower than average. The average duration is 7 days.

For Sleep Number, their company policies are mediocre.

Sleep Number offers a 100-night trial period and a 15-year warranty. Shipping is free, but if the mattress ends up not working out, there is a $49 return fee.

Company Factor	Factor Weight	Score	Data
Trial Period	15%	8.0	100 nights
Warranty	10%	8.0	15 years
Shipping	5%	10	$0
Returns	20%	8.0	$49
Trust	50%	4.0	Terrible
Country of Origin	0%		USA

Comparing all mattresses tested to date, this trial is quite a bit shorter than the 178-night average and the warranty is 2 years longer than average.

The average mattress warranty is 13 years, excluding 25% of mattresses that have a lifetime warranty.

Sleep Number’s major feature is the adjustable firmness based on the user’s preferred Sleep Number. Using the rubber bladder, the Sleep Number score can range from 5 to 100.

We tested several different numbers and took firmness measurements. Here is a summary of our findings:

Sleep Number	Firmness	Feel
25	Very Soft (3.5)	Very deep sinkage, lacks support. I would not recommend sleeping at this level.
50	Medium (5)	A more notable sinkage level, decent support, not great.
60	Medium-Firm (6)	More balanced sinkage level with better support.
75	Firm (8)	Less dramatic floating feel compared to 100, but still pretty dramatic
100	Very Firm (9)	Significant floating feeling

The problem with the lowest sleep numbers (really anything much below 50) is it’s not really softer…it’s just a huge level of sinkage as the rubber bladder is more and more deflated.

At a sleep number of 5, there is so little air in the bladder my body was effectively laying on the foundation of the mattress, hence it felt actually firmer than some of the higher sleep numbers.

Overall support on the Sleep Number mattress is excellent. However, there are some caveats. Most notably, support varies dramatically based on your sleep number.

While the Sleep Number indeed adjusts the firmness, it also adjusts how much support the mattress provides. Higher sleep numbers create better support (albeit, firmer support as well), while lower sleep numbers effectively decrease the level of support.

In our tests, I found that sleep numbers below 50 did not feel supportive. The lower the sleep number, the worse the support was.

At the lowest sleep number, 5, I was sinking so much in the mattress that I effectively bottomed out the mattress and my body was in contact with the mattress foundation itself.

In my view, Sleep Number is best suited to sleepers who need a sleep number in the 50-100 range. A sleep number of 50-100 creates a robust level of support, while still providing adjustable firmness.

This also means that lower sleep numbers, those 45 and under, should generally be avoided, as the compromise in the total support of the mattress is significant (getting more notable as you approach the lowest sleep numbers).

In essence, if you want a medium to extra firm feel, Sleep Number has great support. However, if you want a medium soft, soft, or extra soft feel, you will likely be better served by a different mattress.

Provided your Sleep Number is 50 or higher here are the body types and sleeping positions that the Sleep Number is best suited for.

Sleeper Weight	Stomach Sleepers	Side Sleepers	Back Sleepers
Under 150 lbs.	Yes	Yes	Yes
150-250 lbs.	Yes	Yes	Yes
250-300 lbs.	Yes	Yes	Yes

Design

The Sleep Number bed is designed to be fully adjustable, with a push of a button. It is 9.5″ thick and firmness ranges from very soft (3.5) up to very firm (9).

It comes with the mattress, a remote control, and an air pump that sits below the mattress.

Small clear tubes travel from the air pump into the central rubber bladders of the mattress (one on each side of the mattress).

As you adjust the firmness, air travels through the tubes and adjusts the feel of the mattress.

Materials

The Sleep Number mattress is 9.5″ thick and breaks down into 3 simple layers. From top to bottom, the layers are listed below:

• 1.5” quilted cover
• 2.0” poly foam
• 6.0” adjustable rubber bladder

The Cover

The cover of the Sleep Number C2 mattress is soft and has a quilted finish. It zips off the top of the mattress, making it easy to expose the central layers of the Sleep Number mattress.

The Comfort Layer

Below the cover is a 2.0″ poly foam with a corrugated wave-like pattern to promote pressure relief within certain zones. This layer sits directly below the cover and above the customizable air cavity.

The Support Layer

The support layer itself is the rubber bladder, which fills or releases air to adjust the overall firmness.

Edge foam at the perimeter of the mattress as well as along the center of the mattress has a higher density and helps to support the mattress as the air pressure changes.

While the customization of the central air bladder is nice, the support foam tends to be problematic in some instances.

For example, if you often find yourself on the edge of the mattress or directly in the middle of the mattress, you will be engaging more with that high density foam and not experiencing the benefits of the air cavity.

Product Evolution

The company, Sleep Number, started in the 1980s when they developed and released the first Sleep Number bed that used an inflatable system to change mattress firmness.

Since the initial release over 30 years ago, the Sleep Number mattress has changed greatly, trying new technology and updating or introducing new mattresses.

Current Sleep Number collections include:

• Classic Series
• Performance Series
• Innovation Series
• Memory Foam Series
• Climate360 Series

Other Mattresses to Consider

When looking for alternative options to Sleep Number, you likely won’t find many fully adjustable firmnesses like the Sleep Number.

In the search for a Sleep Number substitute, it would be my recommendation that you identify what firmness is right for you and select a mattress with a single (or dual firmness).

Frequently Asked Questions

Still have questions? Check out some of the top FAQs on the Sleep Number mattress below and get the answers you’re looking for.