sleepnumber vs casper

Disclosure: By clicking on the product links in this article, Mattress Nerd may receive a commission fee at no cost to you, the reader. Read full disclosure statement.

Sleep Number vs. Casper Mattress Comparison

This mattress comparison illuminates the key differences between two mattress industry giants—Sleep Number and Casper—to help you find the best new bed for a good night’s sleep.

Comparing the Sleep Number & Casper Mattresses

The Casper Original is a popular bed-in-a-box foam mattress that provides targeted relief to pressure points. The Sleep Number is an adjustable air bed renowned for enabling you to find the precise amount of air pressure for your sleeping position and comfort level. There are four different Sleep Number bed series, but in this mattress comparison, we’re looking closely at the Performance Series—specifically the p5.  

Overall, the Sleep Number is the best mattress for couples, largely thanks to adjustable firmness levels on each side of the bed. It’s also a better choice for hot sleepers. The Casper is decidedly the better option for budget-conscious shoppers. It’s also better suited to sleepers looking for the close, contouring hug of memory foam.


  • The Casper has one firmness option, while the Sleep Number can be adjusted from zero to 100.
  • The foam layer on top of the Sleep Number mattress serves the simple purpose of simply cushioning your body weight above the air chambers, while the Casper’s foam layers are each designed with a dual purpose: the top layer is responsive and breathable, the middle layer is contouring and pressure-relieving, and the base layer is supportive and improves durability.
  • The Casper and Sleep Number 360 Smart Bed are both conforming, but the Casper has more of the close, contouring feel of memory foam.


  • You’ll experience excellent spinal alignment on both the Casper and Sleep Number.
  • We found both of these beds to be very pressure-relieving.

Sleep Number 360® p5 Smart Bed

Who Should Buy this Mattress? 

  • Combination sleepers
  • Couples
  • Hot sleepers
sleep number p5


Trial period

100 nights


15 years



Who the Sleep Number Mattress is Best For 

Best For…

  • The Sleep Number Responsive Air feature automatically adjusts the air pressure in the mattress to align with your sleeping position, which is ideal for combination sleepers who change positions while they sleep. 
  • Couples can customize their side of the mattress with their preferred firmness level, also known as their “sleep number.” Also, the Queen, King, and Cal King sizes have two distinct air chambers, which ensure that motion doesn’t transfer from one side of the bed to the other.
  • Hot sleepers will stay cooler on the Sleep Number because the air chambers don’t retain heat like foam.

May Not be Best For…

  • Budget-conscious shoppers will likely be deterred by Sleep Number’s luxury pricing.
  • Those who are wary of technology in the bedroom or who want a simple mattress should pass on the Sleep Number since it requires you to use a remote control or the sleep tracking app on your smartphone.

Read our full Sleep Number Mattress Reviews to learn more! 

Casper Original

Who Should Buy this Mattress?

  • Back sleepers
  • Budget-conscious shoppers
  • Those with lower back pain
Casper Original Mattress


Trial period

100 nights


10 year warranty



Who the Casper Mattress is Best For 

Best For…

  • Back sleepers will appreciate the balance of cushion and support provided by the top layer of comfort foam and second layer of zoned memory foam. 
  • Budget-conscious shoppers won’t pay much more than $1,000 for a Queen size Casper mattress.
  • Those with lower back pain will benefit from increased firmness—and thus support—under their hips.

May Not be Best For…

  • Average-weight and heavyweight stomach sleepers probably will sink too deep into the mattress to keep their hips elevated with their shoulders, which is required for spinal alignment.
  • Hot sleepers may find the Casper to retain more heat than is comfortable.

Read our full Casper Mattress Review to learn more! 

Deciding Between Sleep Number & Casper

Firmness / Feel

Mattress firmness is fairly subjective, but companies and reviewers often assign a mattress a firmness score between one and 10. An extremely plush mattress will have a low number, and a table-top firm mattress will have a much higher number. 

Those with heavyweight body types will sink lower into the mattress, which can cause it to feel softer or firmer, depending on the construction. Lightweight sleepers tend to experience mattresses as slightly firmer. 

We scored the Casper at 6/10, which is medium-firm. This firmness level is ideal for back sleepers and side sleepers, but it’s too soft for most stomach sleepers. The Sleep Number suits pretty much every sleeping position, since the Responsive Air feature enables you to customize and maintain your preferred firmness level.

Sleep Number Performance By Sleeping Position:

Lightweight (< 130 lbs):  5 5 5
Average weight (130 – 230 lbs): 5 5 5
Heavyweight (> 230 lbs):  5 5 5

Casper Performance By Sleeping Position:

Lightweight (< 130 lbs):  5 4 4
Average weight (130 – 230 lbs): 5 3 5
Heavyweight (> 230 lbs):  3 2 2

1 = Very poor, 2 = Not good, 3 = Fair, 4 = Good, 5 = Excellent

Motion Isolation

Couples get the best sleep when they aren’t disrupted by their sleeping partner. (The same goes for pet owners and parents.) To avoid disruptions, you need a mattress with the ability to isolate motion. Innerspring mattresses don’t isolate motion very well, but all-foam and memory foam mattresses do. As an all-foam bed, the Casper has excellent motion isolation.

Air beds tend not to isolate motion very well, except those with two parallel air chambers. That’s the case with the Sleep Number in Queen, King, and California King sizes. Because each side of the bed has a separate air chamber, you’re much less likely to experience motion transfer.

Edge Support

Edge support really only matters if you plan to sleep or sit along the edge of your bed. Mattress companies use features like extra firm foam or sturdy coils to reinforce the perimeter of their mattresses. With more supportive edges, you can maximize the space you use, which especially comes in handy if you share your bed.

Even though Casper doesn’t use any distinct edge support technologies in their original mattress, we found the foam layers to be very supportive while both sitting and lying on the side of the mattress. The Sleep Number also supported our weight, though less air in the air chambers causes more sinkage.

Pressure Relief 

Both of these mattresses provide an ideal blend of pressure relief and support. The pressure relief of the Sleep Number is a little difficult to nail down because it’s adjustable, but suffice it to say that you’ll get as much or as little pressure relief as you want. The Casper has a soft top layer and medium-firm Zoned Support transition layer that is more pressure-relieving at the head and foot of the bed where you need a little extra give. 

Spine Alignment 

When we talk about spinal alignment, what we really mean is sleeping posture. Proper spinal alignment looks different depending on your sleep position, but in general, you want your spine to stay in a neutral position from neck to tailbone. For side sleepers, that looks like a straight line when viewed from the side. On your back or stomach, it looks like a gentle “S” curve. 

High-quality foam equally distributes your body weight so the Casper gets an A-grade for spinal alignment in our book. With that said, the Sleep Number gets an A+. Why? It actively adjusts to your sleeping position, so if you move from your back to your side, the air chambers increase or decrease pressure to keep you properly supported.


All-foam mattresses like the Casper tend to have a durable construction that lasts upwards of seven years before the foam begins to lose integrity. Air beds, on the other hand, are more resilient. They typically last up to nine or 10 years, though they are more likely to be fraught with mechanical errors. Fortunately, Sleep Number and Casper cover their mattresses with generous warranties


If you’ve ever slept on an air mattress in a cool environment, you won’t be surprised that an air bed like the Sleep Number can have a cooler temperature profile. The top layer of foam on the p5 actually creates a nice balance in the temperature of the mattress by retaining a touch of warmth. The Casper sleeps a lot warmer, but Casper addresses the tendency of foam to retain heat by perforating (i.e. hole punching) the top layer of foam, which improves airflow. If you’re a hot sleeper, see the best cooling mattresses.

Casper Mattress Construction

0218 CASPER 2020 MATTRESSES SideCompression R2 5 Original
Layers: 3
Cover Recycled polyester
Comfort Layer  Airscape foam
Transitional Layer Memory foam
Support Layer Base foam
Mattress Thickness  11”

The Casper mattress is encased in a fabric mattress cover made from recycled polyester that’s breathable, soft, and durable. The top layer is Casper’s proprietary AirScape foam, which is designed to mimic the responsiveness of latex and the conforming feel of memory foam. The transition layer is memory foam that’s firmer and more supportive under your hips. The base layer of foam is extra firm, which prevents sagging and improves the mattress lifespan.

Sleep Number Mattress Construction

Layers:  2
Cover Polyester and rayon
Comfort Layer  Polyfoam
Support Layer Air chambers
Mattress Thickness  10”

The Sleep Number has a stretchy, soft polyester-rayon mattress cover and a 4” thick top layer of comfort foam. This foam is a proprietary blend made for Sleep Number that’s CertiPUR-US certified. Next, the air chambers (only one in Twin through Full sizes and two in Queen through Cal King sizes) are made of durable rubber and can be adjusted via a mechanical air pump controlled by a remote control or your smartphone. 

Sizing & Price Comparisons 

Mattress Size  Sleep Number Price*  Casper Price 
Twin $1,849 $595
Twin XL $1,999 $695
Full $2,274 $995
Queen $2,399 $1,095
King $2,899 $1,295
Cal King $2,899 $1,295

*Sleep Number states that prices are higher in Alaska and Hawaii.

For additionally dollars off, check out our list of Casper mattress coupons or our list of the best mattress deals.

Shipping and Returns for Sleep Number & Casper

Sleep Number 

The Sleep Number 360 Smart Bed mattresses require in-home setup, so in lieu of a shipping fee, you’ll be required to pay $199 for home delivery and setup. 

The Smart Bed mattresses also come with a 100-night sleep trial. To return or exchange your mattress, you’ll need to test it out for at least 30 days first. If it’s not the right fit, you’ll receive a full refund minus a return delivery fee of $199–$249 plus tax.

The 15-year limited warranty protects you against typical mattress defects, as well as technical malfunctions of the air pump. You receive full coverage during your first year of ownership and then prorated coverage up to 15 years.


Casper mattresses ship for free in the U.S. and Canada, although there is an extra charge for deliveries to Alaska and Hawaii. You can request in-home setup of your new mattress for an extra $149, which includes old mattress removal. 

The 100-night trial period starts the day your mattress is delivered. You can opt for a free return and full refund at any time during the trial period

The 10-year warranty protects against standard manufacturing defects, as long as you’re the original owner of the mattress. Casper will send you a replacement mattress if yours is deemed defective.

More Sleep Number Mattresses

Sleep Number 360 C2

This model is part of the Classic Series, which is the firmest series and has the lowest price range. Rather than a 4” foam layer, the c2 has a 2” comfort foam layer.

sleep number c2 bed

Sleep Number 360 i8

The i8 is part of the Innovation Series, which is Sleep Number’s plushest Smart Bed series. It features a 6” comfort layer, temperature-neutral foam, and an extra breathable mattress cover.

Desktop i8 450x337.jpg

Sleep Number 360 m7

The m7 is Sleep Number’s signature memory foam mattress, featuring a 5” layer of memory foam above the air chambers.

sleep number m7

More Casper Mattresses

Casper Hybrid

The Casper Hybrid mattress pairs the same Airscape foam and Zoned Support transition layer as the original, but subs a foam base with a bouncy, breathable spring mattress foundation.

Casper Original Hybrid Mattress

Read our full Casper Hybrid mattress review for more info.

Casper Wave Hybrid

The Casper Wave Hybrid mattress features patented gel support pods and gel-infused AirScape 3 foam. 

Casper Wave Hybrid Mattress

Read our full Casper Wave mattress review for more info.

Casper Nova Hybrid

The Casper Nova Hybrid mattress is the plushest of the bunch and features a seven-zone ergonomic transition layer.

nova hybrid plain room xl 1

Read our full Casper Nova mattress review for more info.

Our Final Take

These mattresses are so different that choosing between the two really boils down to what you’re looking for. If you want that contouring, cloud-like all-foam feel, then definitely go with the Casper. The Casper is also a better fit for budget-minded shoppers who are looking for a high-quality mattress with a universal firmness. The only folks we think should steer clear are stomach sleepers and those who get really hot at night.

The Sleep Number is a luxury mattress, so it’s higher cost, but you get the adaptability of literally 100 different firmness levels, plus the ability to customize each side of the mattress. For these reasons, we favor it for couples. It’s also a uniquely ideal choice for combination sleepers since the air-fill levels adapt to your changes in sleeping position in real-time.