Casper One Mattress Review

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

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	Casper One	Average
Overall Score	7.83	8.57
Price (Queen)	$995	$1,079 (Foam only)
Cooling – Score	8.0	8.7
Sinkage – Depth	1.77″	2.15″
Sinkage – Feel	Minimal	Moderate
Motion Transfer – Score	8.0	8.2
Motion Transfer – Acceleration	9.42 m/s²	8.79 m/s²
Response Time – Score	9.9	9.0
Response Time – Mostly Recovered	0.2 sec.	0.4 sec.
Response Time – Fully Recovered	0.4 sec.	0.9 sec.
Bounce – Height	8.77″	9.53″
Bounce – Feel	Moderate	Moderate
Edge Support – Score	8.2	8.6
Edge Support – Sitting	3.50″	4.04″
Edge Support – Lying	Fair	Good
Sex – Score	8.3	8.4
Pressure Relief – Score	6.0	8.7
Comfort Layer Thickness	3.0″	4.1″
Mattress Thickness	10″	12.0″
Off-Gassing – Score	6.7	8.1
Off-Gassing – Smell	Strong	Strong
Off-Gassing – Days	12 days	7 days
Company – Score	8.5	8.6
Trial	100 nights	178 nights
Warranty	10 years	25% have lifetime warranties, average of other 75% of mattresses is 13 years

How is Casper One Different?

The Casper One is an all-foam mattress with below-average performance and a price that is also slightly below average—10% less than the average foam mattress.

Advantages

Advantages for the Casper One include faster material response time and better edge support than average.

Neutral Factors

This mattress has 18% less sinkage than average and also less bounce—10% less than the average level. Both sinkage and bounce are considered neutral factors and personal preferences may vary.

The levels of these factors on the Casper One are within a reasonable range that would be considered comfortable for most sleepers.

Disadvantages

Cooling performance is below average and it also has higher levels of motion transfer. Off-gassing is more than twice the average off-gassing period, which could be an issue for sensitive sleepers.

The Casper One has good cooling performance, but it is far from incredible.

During our tests, I felt a slight to moderate level of heat retention around my body. From a cooling perspective, the mattress has a pretty basic all foam design.

The mattress has no cooling features to speak of. No convoluted foam, no gel, no copper, no phase change, no coils, and the all foam design does the mattress no cooling favors.

• 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

In our objective temperature testing, we measured a max surface level temperature of 89.6°, which is just about average. For many sleepers, the Casper One will be cool enough not to be a serious issue.

However, if you describe yourself as a “hot” or “warm” sleeper, you’ll likely find the cooling performance just isn’t good enough. If this is you, then the Casper Snow is likely the better choice.

Heat Dissipation Over Time

The Casper One has a minimal level of sinkage. During our tests, we measured a pressure point sinkage depth of 1.77”. This is 0.38” less sinkage than the average of 2.15”.

The mattress creates more of a “floating” feel for sleeper bodies, as opposed to sinking down “in” the mattress. There is very little body contour and very little hug.

The level of sinkage is documented in the image below.

While some sleepers do prefer this type of a feel, for many sleepers I expect this feel, coupled with the limited 3.0” comfort layer, is going to create pressure relief issues.

Suffice to say, I’m just not blown away with the sinkage and comfort dynamic on the Casper One.

The Casper One has a low level of motion transfer. During our tests, we measured an acceleration range of 9.42 m/s². This is 7.1% more motion transfer than the average of 8.79 m/s².

The minimal level of sinkage is creating much of the excess motion. Mattresses with less motion typically have a more notable level of sinkage. This allows energy to be more deeply and evenly dispersed and dissipated by the foam layers.

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

In the case of the Casper One, those motion events only sink to a minimal level before rebounding up, creating more motion.

In our motion transfer chart, which visualizes our accelerometer data, we can see the highest motion from 0 to 0.15 seconds. Motion drops immediately thereafter and by 0.60 seconds we’ve returned to near-zero levels.

While the motion peak is a little higher than is ideal, the motion duration is quite restrained. The all-foam design and looser thin cover are definitely helping to limit motion, even if the initial spike is a little higher than average.

The Casper One has a very fast material response. During our tests, we measured a mostly recovered response time of 0.2 seconds and a fully recovered response time of 0.4 seconds.

Both of these are notably faster than the averages of 0.41 (mostly recovered) and 0.88 seconds (fully recovered), respectively. While the memory foam layer within the core of the mattress is a little slower relative to the other foams used, it’s not slow by any absolute measure.

The level of responsiveness is documented in the video below.

By coupling the memory foam with other high-response poly foams and a minimal level of sinkage the mattress rebounds back to shape effectively instantly. This makes the mattress easy to move around on and prevents any type of a stuck feeling.

The Casper One has a high level of bounce. During our tests, we measured a total bounce range of 8.77”. This is 0.76” less bounce than the average of 9.53”.

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

Ideally, I like to see a bounce range of 8-12”. The Casper One is on the low end of that range, but still within. The lower bounce is definitely helping to keep motion transfer lower.

While the bounce is lower than average, it’s definitely not “low”. So while sex performance and ease of movement aren’t quite as good as they would be with a high level of bounce, they aren’t severely negatively impacted.

The Casper One was a mixed bag for edge support. While sitting edge support was excellent, lying edge support left something to be desired. In our sitting edge support tests, we measured a sitting sinkage compression of 3.5”. This is 0.54” less sitting sinkage than the average of 4.04”.

My benchmark for “excellent” edge support is 4.0” or less and the Casper One easily exceeded that mark. While sitting on the edge, the mattress retains its shape and I feel well-supported.

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

Edge support while lying on the edge is good, but also far from great. While lying on the edge I felt reasonably well supported, but it also feels like the mattress will struggle to support more moderate and heavier weighted bodies.

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

The relative thickness of the mattress as a whole, coupled with good, but not great material quality, creates a mattress edge that is lacking.

In addition, there is no reinforced edge, no permitter support foam, and a fairly thin 10” all-foam design. None of these factors are doing the Casper One any favors with respect to edge support.

The Casper One has excellent sex performance. We measured bounce at a “moderate” 8.77” level. Certainly, more bounce is better for sex performance, but 8.77” is enough so that the mattress works with you.

In addition, edge support while sitting was sufficiently strong to earn good marks there as well. That said, the lack of coils does create a rhythm problem for the dance without pants.

Even so, it’s a comfortable enough surface that doesn’t sink too deeply, rebounds a reasonable level of energy, and has good enough bounce. For most sleepers, I don’t foresee the horizontal hokey pokey to be problematic. 

How Do We Determine Sex Score?

The best mattresses for sex have high bounce, good edge support, quiet materials, and good pressure relief and cooling.

These 5 factors make up the NapLab sex performance score.

Sex Factor	Factor Weight	Score	Rating
Bounce	65%	8.0	High
Edge Support	20%	9.4	Excellent
Noise	5%	10	Minimal
Pressure Relief	5%	6.0	Mediocre
Cooling	5%	8.0	Good

These are solid sex scores, but nothing particularly special.

The Casper One has a mediocre level of pressure relief at best. During our tests, I felt a moderate level of pressure points building on my body, especially on my back. Fundamentally, this is a basic all-foam mattress.

We have a limited 3.0” comfort layer with a thin total 10.0” design (Casper’s website says it’s supposed to be 11”, but ours was only 10”).

Thinner mattresses often struggle with pressure relief, as do mattresses with a thinner comfort layer.

The average comfort layer thickness based on all of our tests to date is 4.1”. Casper One’s 3.0” comfort layer is well short of the average.

The overall average total mattress height is 12.0”, where again, Casper is well short of average.

The comfort foams simply don’t have much give to them. This results in the body coming into more significant contact with the support foam, which is quite hard.

While lying in the same position for just a few minutes at a time I could feel pressure points building up, especially in my back. The Casper One definitely isn’t an expensive mattress, but at nearly $1,000 I expect far better pressure relief than what the Casper One was able to deliver. 

Off-gassing on the Casper One is strong right out of the box and the odors take 12 days to dissipate fully.

For reference, the average off-gassing period is 5.86 days so the Casper One is more than double the average.

Casper’s company terms and conditions are pretty typical compared to what we see across the industry. They offer a 100-night trial period and a 10-year warranty on any of their mattresses.

Comparing all mattresses tested to date, the average trial length is 164 nights so Casper’s trial is shorter than average. That being said, 100 nights should still be enough time for you to properly decide if you like the mattress or not.

How Do We Determine Company Score?

The company score takes a look at factors that may influence your experience with the mattress.

Factors include length of the trial period, warranty, shipping / return costs, and country of origin.

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

For Casper, these individual terms and conditions generated a company score of 8.5.

The Casper One has a medium-firm feel with a firmness rating of 6 out of 10.

This is a balanced firmness level and tends to have the widest appeal among different sleeper types.

The Casper One has good support, but not incredible. During our tests, I felt well-supported by the mattress. However, the pressure relief issues are undoubtedly going to cause problems for some sleepers.

For a mattress to create great support it needs to be comfortable enough that you can lie in the same position, while also keeping your body in alignment.

The Casper One does a good job of keeping the body in general alignment. However, the pressure relief issues simply make it less comfortable to lie in the same position.

At just 140 pounds, I felt notable pressure relief issues during our testing. In my view, moderate-weighted and heavier-weighted bodies, in addition to side sleepers, are most likely to experience support issues.

Lighter-weighted bodies as well as back and stomach sleepers are less likely to experience issues.

Check out the table below to see the sleeper weights and sleeping positions that would be best suited for this mattress.

Sleeper Weight	Stomach Sleepers	Side Sleepers	Back Sleepers
Under 150 lbs.	Yes	Yes	Yes
150-250 lbs.	Maybe	Maybe	Maybe
250-300 lbs.	No	No	No

Design

The Casper One is the only all-foam mattress offered within the new Casper mattress lineup (released in 2024). It is 10″ thick and has a medium-firm feel (6 out of 10).

Materials

This mattress has a total thickness of 10.0″. According to Casper’s website, the thickness should be a full 11″, but that was not the case with the mattress we were shipped.

• 1.5” poly foam
• 1.5” memory foam
• 7.0” support foam

The Cover

The cover of the Casper One is a thin, knit-blend that has good stretch and breathability. There is no tufting and no quilting.

The Comfort Layer

The comfort layer contains two layers of foam. On the top, we see a 1.5″ poly foam followed by a 1.5″ memory foam. Both of these foams work together to give the Casper One a balanced feel.

The Support Layer

The support layer of the Casper One is a 7.0″ support foam. This layer supports the weight of the sleeper above, without the use of coils or springs.

Product Evolution

Casper originated in 2014 with its launch of the Casper all-foam mattress. In 2019, Casper hybrids entered the chat and models continued to be added until it hit max capacity in 2023.

In early 2024, Casper discontinued their entire mattress line and launched 5 brand-new mattresses.

Prior to this rework, there were 3 Casper foam mattresses:

• The Casper
• Casper Original
• Casper Select (Costco exclusive)

Casper’s 2024 lineup includes:

• Casper One – all foam, most basic, least expensive
• Casper Dream – least expensive hybrid
• Casper Dream Max – higher performance hybrid
• Casper Snow – least expensive, cooler hybrid
• Casper Snow Max – higher performance, cooler hybrid

As of January 2024, Casper has updated the fire barrier of their mattresses, including the Casper One. The previous fire barrier, which contained fiberglass, has now been updated to use a Rayon fiber-based product instead of the traditional fiberglass.

Other Mattresses to Consider

Not sure if the Casper One is the right pick for you? Check out these three other top-rated foam mattresses for high-performing alternatives you may want to consider.

Frequently Asked Questions

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

Disclosure – Derek Hales has a history with Casper that some may view as relevant to his reviews of Casper products. In 2016, Casper Sleep sued Derek Hales in federal court over his reviews of its products. In 2017, the lawsuit ended with a settlement. See here for more information.