How to Choose a Memory Foam Mattress: Specs That Matter
Memory foam mattresses look alike online, so the decisions come down to a handful of details the brand pages already list.
By WellnessTrim Editorial Team
7 min read
A memory foam mattress page can read like a spec sheet: a firmness word, a number out of ten, a stack of layer names, a certification or two, and a trial length. None of it is hard to read once you know what each line is describing, and which lines the brand has chosen not to fill in.
This article walks through the details that change what a mattress feels like and what happens after it arrives, using the five models in our best memory foam mattress guide as examples. Every figure below comes from what each brand publishes on its own product page, checked on October 12, 2026. Terms and prices change, so confirm them on the brand page before you order.
Settle on firmness first
Firmness is the hardest thing to correct later, so it is worth deciding before you compare anything else. Brands describe it in two ways: a word, or a word plus a number out of ten. Both come from the brand, and the scale is the brand's own, so a 5 on one page is not a promise about a 5 on another.
- WinkBeds sells the GravityLux in Soft, Medium and Firm versions, and lists comfort levels of 4 for Soft, 5 for Medium and 7 for Firm.
- Nolah lists the Original as Medium-Firm (5-6/10).
- Saatva lists the Contour5 as Medium (5-7/10).
- Leesa lists the Original as Medium comfort, and Amerisleep lists the AS3 as Medium.
One extra line is easy to miss: recommended sleep positions. Amerisleep lists side and back for the AS3, while Saatva describes the Contour5 as ideal for side sleepers but also great for back and combination sleepers. If you share a bed, the feel you choose has to work for two people, which is one reason a model with more than one firmness option can be easier to buy.
Try This: Write down the feel you currently sleep on and the one thing you would change about it, then use that sentence to filter the brand's own firmness scale before you look at price.
Read the layer stack, not just the height
Height tells you how much material is in the mattress; the layer list tells you how it is arranged. Both matter, for different reasons.
On height, the Leesa Original and the Nolah Original are both listed at 10 inches, while the Amerisleep AS3 is listed with a 12-inch profile. WinkBeds and Saatva do not list an overall height in the details we reviewed. A taller mattress sits differently in a bed frame and changes which sheets fit, so it is worth checking against what you already own.
On the stack itself, brands usually list layers from the cover down to the base:
- Leesa lists a 4-layer build with 2 inches of GreenFlex BioFoam, 2 inches of memory foam and 6 inches of support foam.
- Saatva lists a 3-inch layer of ultra-premium, high-density 5lb memory foam over a highly durable support foam base.
- WinkBeds lists a TENCEL cover with gel-infused foam, AirCell memory foam, Progression Foam and an ATLAS Core foam at 1.8lb density, with 7 support layers.
- Nolah lists six resilient foam layers, including copper-infused Cool Contouring Foam, Tri-Zone Foam and a 4-inch stabilizing base layer.
Density is listed in pounds per cubic foot, and only some brands publish it. Where both pages give a figure, you are comparing the same unit. WinkBeds describes its 1.8lb density ATLAS core foam as providing pushback support and sag-proof lifetime durability, and Saatva describes its memory foam layer as ultra-premium and high-density, so read those as the brand's own descriptions rather than a shared standard.
Try This: List the layers in order from cover to base on two product pages side by side; the top two or three entries are the ones that shape the initial feel.
Find out where the cooling sits
Cooling is not one feature. It can sit in the cover, in a comfort layer, or arrive only as a paid upgrade, and the pages above show all three approaches.
- WinkBeds puts 2 inches of premium cooling gel foam inside a TENCEL cover and lists temperature-regulating features for sleeping cooler than many all-foam models.
- Leesa lists a breathable knit cover, with a cooling quilt top upgrade described as cool-to-the-touch with added cushioning.
- Nolah uses copper-infused Cool Contouring Foam and offers a cooling pillow top upgrade.
- Amerisleep lists plant-based Bio-Pur memory foam, HIVE technology for airflow, and cooling technology on the spec sheet.
- Saatva lists adaptive cooling technology and a CoolVent System that it says absorbs and disperses excess body heat.
If you sleep warm, the useful question is not whether cooling is mentioned but where it sits and whether it is included in the price you are looking at. A cooling quilt top and a cooling pillow top are upgrades on two of these models, which means the base version is built without them.
Try This: Note whether the cooling feature is in the cover, in a comfort layer, or an optional upgrade, then compare only models at the same level.
Decode the certifications and materials
Certifications are one of the few lines that can be checked against an outside program, so it is worth knowing which ones these pages list and which they leave out.
- Leesa says all its foams are CertiPUR-US certified and describes the fire barrier as chemical-free and fiberglass-free.
- Saatva lists CertiPUR-US certified foams and GREENGUARD Gold certification, an endorsement from the American Chiropractic Association, and an exclusive Guardin botanical antimicrobial treatment that it says inhibits the growth of bacteria, mold and mildew.
- Nolah lists GREENGUARD Gold certified and CertiPUR-US certified foam, and describes the mattress as fiberglass-free.
- Amerisleep describes the AS3 as fiberglass-free, eco-friendly and non-toxic.
- WinkBeds and Amerisleep do not list a foam certification in the details we reviewed, so ask the brand directly if that matters to you.
Certification wording belongs to the manufacturer, so read the current page rather than an old review. On setup and care, follow the manufacturer's instructions for your model, and speak with a healthcare professional if you have an injury or a condition that affects how you sleep. Our medical disclaimer explains our approach.
Try This: Copy the exact certification names from the brand page into a note, and check whether each one applies to all the foams or only some of them.
Weigh the trial and the warranty
Trial length is the easiest number to compare, but the wording around it is what usually matters: who pays return shipping, what condition the mattress has to be in, and whether the warranty replaces the mattress or repairs it.
- Amerisleep lists a 100-night risk-free sleep trial with free shipping and returns, and a 20-year warranty.
- WinkBeds lists a 120-night risk-free trial, free shipping and returns, and a full replacement lifetime warranty alongside a DuraTech lifetime durability score and replacement guarantee.
- Leesa lists a 365-night trial with free shipping in its features, and a limited lifetime warranty.
- Saatva lists a 365-night home trial, with no warranty term in the details we reviewed.
- Nolah lists a limited lifetime warranty, with no trial length in the details we reviewed.
So on these pages the trials range from 100 nights to 365 nights, and the warranties split between a 20-year term, a full replacement lifetime warranty and a limited lifetime warranty. Limited and full replacement are different promises, and a lifetime term only helps if you know what it covers.
Try This: Before ordering, note the trial length, who pays return shipping and what the warranty replaces, and keep the order confirmation where you can find it.
Check the base, sizes and weight
The last group of specs decides whether the mattress works in your bedroom as it is. Base requirements come first, because not every brand publishes them.
- Nolah says to use the Original on any flat surface, with slats no more than 5.5 inches apart, and lists compatibility with adjustable bases.
- Saatva lists a mattress foundation or box spring plus a bunkie board.
- WinkBeds, Leesa and Amerisleep do not list base requirements in the details we reviewed, so confirm with the brand before ordering.
Sizes and weights are listed per model, and they are not quite identical across brands. WinkBeds lists a Twin at 38" x 75", a Queen at 60" x 80" and a Cal. King at 72" x 84". Leesa lists a Queen at 60" x 80" x 10" and 71 lbs, a King at 90 lbs and a Cal King at 92 lbs, while Amerisleep lists its Queen at 60" W x 80" L x 12" H. One small example of why you check: the Full size reads 54" x 75" on the WinkBeds page and 53" x 75" on the Leesa page.
Weight is worth a glance too. Leesa lists a Twin at 45 lbs and a King at 90 lbs, which is the difference between a mattress one person can move and one that needs help.
Try This: Measure your frame and the gaps between your slats before you order, then check that exact model's base requirement and listed weight.
The Bottom Line
Firmness, the layer stack and the placement of cooling decide how the mattress feels, while certifications, trial terms, warranty wording, base requirements and weight decide how the purchase goes. The five models in our best memory foam mattress guide cover the range, from a single medium feel to a model sold in Soft, Medium and Firm. Confirm the current specs and terms on the brand page before you buy, and follow the manufacturer's setup instructions.
General information only, not medical advice. Talk to your doctor before making big changes to your diet, exercise or sleep, especially if you have a health condition or take medication. See our medical disclaimer and editorial policy.
