The Sleep Science line of mattresses is manufactured by South Bay International, and most of these models are built with memory foam. These mattresses are sold in Costco and through Costco’s website and offer many potential values for those seeking this type of mattress.

Some of the key strengths of the Sleep Science mattresses include

  • Many size and price options: with numerous mattress models and price points, sleepers can identify the Sleep Science mattress that best fits their firmness preference and budget.
  • Costco return policy: the warehouse store has a strong reputation for service and returns, which gives customers an opportunity to test out the mattress for an extended period.
  • Strong motion isolation: most of the Sleep Science mattresses have a top comfort layer of high-density memory foam, and one of the biggest strengths of this type of material is its motion isolation. For people sharing a bed, motion isolation helps ensure that one person’s movements don’t disturb the other.

Potential drawbacks for the Sleep Science mattresses include

  • Only available through Costco: because these mattresses are only available through Costco, they are not a viable option for people who aren’t Costco Warehouse members.
  • Negatives of memory foam: memory foam mattresses aren’t right for all sleepers as some customers find them to have too much sink and be too hot and, too restrictive of movement.


Sleep Science Mattress Pricing

Pricing for the Sleep Science line of mattresses varies significantly based on the model and the size. The table below gives the range of prices for each model.

Mattress Model Price Range
(varies by size, typical range twin to king)
8” Dream $279.99 – $499.99
10” Active Studio Plush $449.99 – $949.99
10” Marina $469.99 – $799.00
10” Sleep Science $319.99 – $599.99
11” Black Diamond $529.99 – $999.99
11” Carina Gel $619.99 – $1,099.99
12” Active Loft Plush $579.99 – $1,099.99
12” Iflip Sonoma
$599.99 – $749.99
13” Ara $1,099.99 – $1,299.99
14.5” ESCAPE Luxury $1,499.99 – $1,799.99


Interested in a Sleep Science mattress?


About the Sleep Science Mattresses

Sleep Science Mattresses Specifications

Sleep Science manufacturers 9 different models of memory foam mattresses. Each has a different composition and set of specifications, as described in the table below.

Mattress Model Specifications
8” Dream Top: 3” memory foam
Middle: 2” support foam
Bottom: 2” support foam
10” Active Studio Plush Top: 1.5” 4 PCF memory foam
Middle: 1.5” 3 PCF support foam
Bottom: 7” support foam
10” Marina Top: 3” 3 PCF gel-infused memory foam
Middle: 2” air-comfort support foam
Bottom: 5” support foam
10” Sleep Science Top: 3” memory foam
Middle: 2” support foam
Bottom: 5” support foam
11” Black Diamond Top: 1” 5 PCF memory foam
Second: 1” 5 PCF memory foam
Third: 2” latex
Bottom: 7” support foam
11” Carina Gel Top: 2″ 3 PCF gel-infused memory foam
Second: 2″ 4 PCF memory foam
Third: 1″ latex
Bottom: 6” support foam
12” Active Loft Plush Top: 2” 4 PCF memory foam
Middle: 2” 4 PCF memory foam
Bottom: 8” support foam
12” Iflip Sonoma
Top: 2” 3 PCF/ 10 ILD memory foam
Second: 2” support foam
Third: 4” support foam
Fourth: 2” support foam
Fifth: 2” 3 PCF / 13 ILD memory foam
13” Ara Top: 3” 5 PCF memory foam
Second: 3 3/8” 5 PCF memory foam
Third: 3/8” support foam
Fourth: 6” support foam
14.5” ESCAPE Luxury Top: 1/2” quilted foam pillow top
Second: 2” 7 PCF /11-13 IFD memory foam
Third: 3” 5 PCF / 11-13 IFD memory foam
Fourth: 9” support foam

In some cases, neither Sleep Science nor Costco list the detailed information about the full specifications. For example, some of the foam densities are listed while others may not have that information available.

Many of these mattresses are also advertised with specific features based on their composition. This is a brief overview of some of these that you may find in the product descriptions:

  • Wedge support system: this uses a wedge-shaped piece of foam near the edge of the other mattress the layers. The goal of this system is to enhance the edge support of the mattress.
  • Air-channel base: small grooves are cut into some of these mattresses support foams in order to try to prevent heat retention and allow airflow for cooling.


Where It’s Made

Sleep Science mattresses are manufactured either in a privately-owned factory in China or by one of the company’s manufacturing partners based in the USA.

Buying Logistics

Sleep Trial / Refunds

Costco extends its standard customer satisfaction policy to mattresses. While this is generally regarded as a generous return policy for a retail outlet, there is no specific timeframe stated as it applies to mattresses. It is reasonable to expect that a timeframe similar to many online sleep trials, such as 100 days, would be available from Costco for Sleep Science mattresses; however, this is not formally in writing on the Costco website where the purchase would be made.

It is also important to note that, according to the Costco website, mattresses must be returned to the store. This may be a challenge for some customers depending on the type of vehicle they own and how far they are from the nearest Costco.


Most Sleep Science mattresses are compressed and delivered to your door in a box. Once the mattress is removed from the box and packaging, it decompresses to reach its full size. This usually happens within a few hours but can take longer depending on the temperature of the room and the mattress.

The cost of delivery is included in the price of the mattress for customers in the continental U.S. Shipping via FedEx ground usually occurs within 7-10 days after the mattress is ordered. However, all mattresses are subject to availability, so it is important to check the website for specific delivery timeframes.

Two of the Sleep Science mattresses — the Ara and the ESCAPE — come with white glove delivery. This means that delivery also includes unboxing and setup. In some cases, the company may be able to haul away an old mattress, but if possible, this must be coordinated ahead of time.


Sleep Science mattresses come with a 20-year warranty against manufacture defects. Details on the warranty are not available online and must be obtained directly from the company.

Customer Service

Costco has a longstanding reputation for customer service, and this extends to the Sleep Science mattress products sold through the company. South Bay International, which manufactures the Sleep Science line of mattresses, has been in business for 23 years and has an A+ rating from the Better Business Bureau.


Mattress Performance

Overall, the Sleep Science line of mattresses offers many options for people who are interested in sleeping on memory foam. While the exact firmness level and performance can vary based on the model, you can expect these mattresses to reflect the typical characteristics of memory foam.


Memory foam mattresses are generally thought of as supportive through their contouring properties. Because the foam indents based on the amount of weight and pressure applied, it can hug the body to provide support where it is needed most. Many sleepers find this to be extremely comfortable while others find that it can seem to create spinal misalignment.

For sleepers who want a memory foam mattress, Sleep Science likely offers a model that can meet your needs. For those wanting a more supportive mattress, consider one of the models with a higher-density top layer.


There is limited hard data about the Sleep Science mattresses, and durability may vary from model to model because of the different quality of materials that are utilized in each. Models that have lower-density support foams are more likely to suffer from long-term durability problems, but unfortunately, Sleep Science and Costco do not reveal the density of all of the layers of all of their mattresses.


Most memory foam mattresses are not considered to be as firm because of the level of sink that occurs when weight is applied to the mattress, but it is necessary to keep in mind that this can vary based on the foam density.

For the Sleep Science models, most are a mid-range firmness level. However, the softest models are the Marina, Dream, and Ara. The firmest are the Black Diamond and the Carina models. The Iflip model has different firmness on either side, allowing you to choose between a firmer or softer mattress depending on how you have the mattress aligned.

Motion Transfer

Strong motion isolation is a hallmark of memory foam mattresses, and the Sleep Science models typically have received positive marks from reviewers and customers for their motion isolation.


You should expect some level of offgassing from the Sleep Science memory foam mattresses. Every individual’s perception of the smell is different, but the company itself says that it may take 24-48 hours before the smell dissipates. Most customers have confirmed this to be the case; however, extremely smell-sensitive customers may want to choose mattresses made with materials other than memory foam.

Sleeping Hot

While the hugging properties of memory foam can make these mattresses extremely comfortable, they can also cause people to sleep hot. This is especially the case because memory foam become more responsive as its temperature increases, which can increase the amount of sink or hug during sleep.

Many of the Sleep Science models include descriptions about increasing air flow or temperature regulation, but it is hard to truly judge the effectiveness of these design features. While the company may have invested in manufacturing their mattresses to try to limit the “sleeping hot,” problem, many customers still find heat retention to be an issue comparable to most memory foam mattresses.


Because memory foam sinks when pressure is applied, it can make moving in bed more difficult and can pose some obstacles to sexual activity. A more firm model or a mattress made of latex or innerspring coils may be a better choice for consumers concerned about finding the optimal mattress for sex.

Mattress Comparison

The table below provides a comparison of some mattresses with similarities to the Sleep Science line of mattresses in terms of construction and feel.

Brand Mattress Type Support Layer Comfort Layer Price (Queen) Where to Buy
Sleep Science Foam Foam Memory Foam Varies Costco (including online)
Purple Foam Foam Hyper-Elastic Polymer $999 Online only
WinkBed Hybrid Pocketed coils Coils + Foam $1,299 Online + 1 showrooms
GhostBed Latex Hybrid Foam Memory Foam + Latex $795 Online only
Leesa Foam Foam Avena Foam $940 Online only


Interested in a Sleep Science mattress?

by: Eric Seger