Best Mattress on Amazon
A mattress "firmness 6" is a number the brand gave itself. There is no industry body auditing the 1–10 scale, no standard it is measured against, and nothing requiring one brand's 6 to feel like another's. Meanwhile a real measurement exists: ILD, defined under ASTM D3574 as the pounds of force needed to compress a standard 15×15×4 in foam sample by 25% — and almost no brand publishes it, precisely because it is the one number a shopper could hold against a competitor. So buy from the spec sheets that disclose: Brooklyn Bedding publishes layer ILDs on the Signature Hybrid and the Plank Firm. And remember firmness is not a property of the mattress alone — a sleeper over ~230 lb compresses through the comfort layer, so the same bed feels softer than its label.
Non-disclosure is not misconduct — but it is information. The absence of ILD does not mean a mattress is poorly made; it means the firmness claim cannot be independently verified. Brands that publish usually do so because they also sell raw foam to technical buyers, not because anyone requires it. See why firmness scales aren't standardised and which mattresses publish ILD.
Who publishes a verifiable number
| Brand / model | What the spec sheet actually gives you |
|---|---|
| Brooklyn Bedding Signature Hybrid | Layer ILDs — quilt ~13, TitanFlex ~18, transition ~28 |
| Brooklyn Bedding Plank Firm | Core 1.8 lb density / 36 ILD, plus a 3.5 lb / 28 ILD fast-response layer |
| Saatva, Nectar, Avocado | No ILD for any layer — a self-assigned house-scale number only |
| Purple, Tempur-Pedic | No ILD, and correctly so — neither comfort layer is standard polyurethane foam |
Full table: The Firmness Translation Index. Detail on the measurement: what is ILD? and what firmness 7 actually means.
The same mattress is a different mattress by body weight
| Sleeper weight | What actually happens |
|---|---|
| Under ~130 lb | Sits nearer the top of the comfort layer and feels its true surface firmness |
| Over ~230 lb | Compresses through the comfort layer into the firmer support core — the same bed can feel noticeably softer than its label |
See does body weight change firmness? and best firm mattress for heavier sleepers.
Firmness by sleep position
| Position | Typical range | Why |
|---|---|---|
| Side sleepers | Roughly "soft" to "medium" | Lets the shoulder and hip sink in enough to keep the spine level |
| Back sleepers | "Medium" to "medium-firm" | Balances cushioning against enough support to stop the hips sinking too far |
| Stomach sleepers | "Medium-firm" to "firm" | Stops the midsection sinking and pulling the lower back out of alignment |
General equipment-fit guidance, not medical advice. See side sleepers, back sleepers, and stomach sleepers.
Best disclosed spec sheets: Brooklyn Bedding
Publishes ILD numbers for multiple internal layers, not just a single headline figure — the most transparent spec sheet in this dataset.
Best for: Combination sleepers (back/side) wanting a documented middle-of-the-road feel with real coil support. Watch out: Even with published ILD, Brooklyn Bedding's own firmness label ('Medium') is still self-assigned — always cross-check the ILD numbers themselves, not just the word.
One of the very few firm-tier mattresses with an actual published ILD number for both major foam layers, not just a marketing label. Watch out: All-foam construction sleeps warmer than a coil-based firm mattress, and the flippable dual-firmness design means the 'other side' is even firmer than most shoppers expect from the word 'firm.'
Soft band
Saatva Classic Plush Soft — One of the few soft-tier mattresses that still uses a full coil support core, so it stays soft on top without losing edge support or airflow. Watch out: Saatva's own firmness numbers are a HOUSE scale, not an industry standard — its 'Soft (4)' will not feel identical to another brand's '4'. ILD for the pillow-top layer is not publicly disclosed.
Nectar Original Mattress — Deep, slow-recovery memory-foam contouring at a lower price point than most latex or hybrid soft-tier beds. Watch out: Memory foam sleeps warmer than latex or coils and has a slower response — turning over can feel like fighting the mattress. No ILD figures are published for any layer.
See best soft mattress and best firmness for side sleepers.
Medium band
Avocado Green Mattress — Natural latex has a quicker, more buoyant response than memory foam at a comparable firmness label, which changes how a given ILD (if it were published) would actually feel. Watch out: No ILD numbers are published for the latex layer, and natural latex firmness varies somewhat batch-to-batch versus synthetic foam, which the brand does not quantify.
Purple Original Purple Mattress — The grid buckles under pressure points (hips/shoulders) while staying firmer under lighter-loaded areas, which behaves differently from a uniform-ILD foam layer. Watch out: Because the comfort layer isn't foam, ILD simply doesn't apply to it — any 'ILD equivalent' you see quoted online is an estimate, not a manufacturer figure, and the grid can feel firmer at first touch than the 'medium-firm' label suggests.
Tempur-Pedic TEMPUR-Adapt Medium — TEMPUR material is pressure- and temperature-responsive in a way standard PU foam isn't, which is part of why the brand doesn't publish a standard ILD figure for it. Watch out: Because it's a proprietary material family, you cannot compare its firmness to a PU-foam ILD number at all — the 'Medium' label is only comparable to Tempur-Pedic's own Soft/Medium/Firm lineup, not to competitors.
See best medium-firm mattress and memory foam vs latex vs hybrid.
Firm band
Saatva Classic Firm — Keeps a traditional coil-on-coil support system rather than switching to all-foam at the firm end, which some stomach/back sleepers prefer for a 'sleeping on top of' feel. Watch out: Same house-scale caveat as its Soft sibling — Saatva's '8' is not directly comparable to another brand's '8', and no ILD figure is published for the comfort layer.
See best firm mattress.
Why identical ILD still feels different
Memory foam has a slow, viscoelastic recovery that deepens the sink-in at a given ILD. Latex responds quickly and feels buoyant at a comparable ILD. A hybrid's coil core adds bounce and can make a soft comfort layer feel more supportive than the same foam over an all-foam base. So a 28-ILD latex layer and a 28-ILD memory-foam layer will not feel the same — ILD is only directly comparable within similar constructions.
The picks
Research-based picks (how we evaluate), from published constructions, manufacturer firmness labels and — where they exist — disclosed ILD figures. Not hands-on sleep testing. Live Amazon search links, no prices or ratings, an honest drawback on each.
Saatva Classic Plush Soft
Innerspring hybrid, self-reported 'Soft' (~4/10 house scale), euro pillow-top comfort layer, dual coil support core
One of the few soft-tier mattresses that still uses a full coil support core, so it stays soft on top without losing edge support or airflow.
Best for: Lighter-weight side sleepers who want pressure relief at the shoulder/hip without an all-foam feel
Watch out: Saatva's own firmness numbers are a HOUSE scale, not an industry standard — its 'Soft (4)' will not feel identical to another brand's '4'. ILD for the pillow-top layer is not publicly disclosed.
Check price on AmazonBrooklyn Bedding 3" Latex Topper — Soft
Natural Talalay latex topper, manufacturer-published comfort ILD 19 (soft tier of a 19/28/36 lineup), 3 in thickness
A rare case where the brand actually publishes the ILD number on the spec sheet, so you can compare it directly to their own medium (28 ILD) and firm (36 ILD) versions.
Best for: Side sleepers wanting to soften an existing firm mattress rather than replace the whole bed
Watch out: A topper only changes the top few inches — it doesn't change the support core underneath, so a very firm base can still feel firm through a soft topper for heavier sleepers. Note this specific topper is not currently listed on Amazon (the brand sells mattresses there, but we could not find this topper), so buying it means going direct; the link below shows comparable soft Talalay latex toppers available on Amazon.
Check price on AmazonNectar Original Mattress
All memory-foam construction, self-reported 'Medium Firm' by brand (~6/10) but third-party reviewers commonly score it softer (~5-6) at the shoulder/hip; ILD not disclosed
Deep, slow-recovery memory-foam contouring at a lower price point than most latex or hybrid soft-tier beds.
Best for: Budget-conscious side sleepers who want a classic slow-sink memory-foam feel
Watch out: Memory foam sleeps warmer than latex or coils and has a slower response — turning over can feel like fighting the mattress. No ILD figures are published for any layer.
Check price on AmazonBrooklyn Bedding Signature Hybrid
Hybrid (foam comfort layers + pocketed coil core), self-reported 'Medium' tier of a Soft/Medium/Firm lineup, manufacturer-published layer ILDs (quilt ~13, TitanFlex ~18, transition ~28)
Publishes ILD numbers for multiple internal layers, not just a single headline figure — the most transparent spec sheet in this dataset.
Best for: Combination sleepers (back/side) wanting a documented middle-of-the-road feel with real coil support
Watch out: Even with published ILD, Brooklyn Bedding's own firmness label ('Medium') is still self-assigned — always cross-check the ILD numbers themselves, not just the word.
Check price on AmazonPurple Original Purple Mattress
Proprietary hyper-elastic polymer grid (not foam) over a support-foam core, self-reported 'Medium-Firm', 2 in grid comfort layer, no published ILD (grid isn't rated on the foam ILD scale)
The grid buckles under pressure points (hips/shoulders) while staying firmer under lighter-loaded areas, which behaves differently from a uniform-ILD foam layer.
Best for: Back and stomach sleepers, or combination sleepers who want targeted pressure relief without a deep foam sink
Watch out: Because the comfort layer isn't foam, ILD simply doesn't apply to it — any 'ILD equivalent' you see quoted online is an estimate, not a manufacturer figure, and the grid can feel firmer at first touch than the 'medium-firm' label suggests.
Check price on AmazonDreamCloud Premier Rest Mattress
Hybrid (memory foam comfort layers + pocketed coils), brand self-reports 'Medium Firm' at roughly 6.5/10 on its own scale, ~3.5 in combined comfort layer, ILD not disclosed
A quilted euro-top over coils gives a cushioned surface feel while the coil core keeps the 'medium-firm' support rating from sinking too far.
Best for: Combination sleepers wanting a hybrid feel at a lower price than premium hybrids
Watch out: No ILD figures are published for any comfort layer, so 'medium firm' here is entirely the brand's own subjective label with nothing to independently verify it against.
Check price on AmazonCasper Original Mattress
All-foam with zoned transition layer (softer at shoulders, firmer at the lumbar/hip zone), brand self-reports 'Medium' (~6/10); independent reviewer panels commonly score it 6-7/10; ILD not disclosed by zone
Zoning means the comfort layer is intentionally NOT one uniform firmness — softer under the shoulders, firmer under the hips — which a single ILD number couldn't capture even if published.
Best for: Back and combination sleepers wanting zoned support without a coil system
Watch out: Because the layer is zoned, there's no single ILD figure that would even describe it accurately, and Casper does not publish per-zone numbers — you're relying entirely on the brand's descriptive marketing.
Check price on AmazonTempur-Pedic TEMPUR-Adapt Medium
Proprietary TEMPUR viscoelastic material (not standard polyurethane foam) over a support foam base, self-reported 'Medium', ~3 in comfort layer, no ILD published (material isn't rated on the standard polyurethane ILD scale)
TEMPUR material is pressure- and temperature-responsive in a way standard PU foam isn't, which is part of why the brand doesn't publish a standard ILD figure for it.
Best for: Side and combination sleepers who want slow, body-conforming contouring
Watch out: Because it's a proprietary material family, you cannot compare its firmness to a PU-foam ILD number at all — the 'Medium' label is only comparable to Tempur-Pedic's own Soft/Medium/Firm lineup, not to competitors.
Check price on AmazonAvocado Green Mattress
Natural Dunlop latex comfort layer over pocketed coils, self-reported 'Medium Firm' (brand states ~6-7/10), ~2 in latex comfort layer, ILD not disclosed by the brand
Natural latex has a quicker, more buoyant response than memory foam at a comparable firmness label, which changes how a given ILD (if it were published) would actually feel.
Best for: Back and stomach sleepers wanting a responsive, less heat-retentive alternative to memory foam
Watch out: No ILD numbers are published for the latex layer, and natural latex firmness varies somewhat batch-to-batch versus synthetic foam, which the brand does not quantify.
Check price on AmazonSaatva Classic Firm
Innerspring hybrid, self-reported 'Firm' (~8/10 house scale), thinner comfort layer over a dual coil support core
Keeps a traditional coil-on-coil support system rather than switching to all-foam at the firm end, which some stomach/back sleepers prefer for a 'sleeping on top of' feel.
Best for: Stomach and back sleepers, and heavier-body-weight sleepers who compress a softer mattress too far
Watch out: Same house-scale caveat as its Soft sibling — Saatva's '8' is not directly comparable to another brand's '8', and no ILD figure is published for the comfort layer.
Check price on AmazonBrooklyn Bedding Plank Firm (Firm side)
All-foam flippable mattress, manufacturer-published core spec 1.8 lb density / 36 ILD with a 3.5 lb / 28 ILD fast-response layer, self-reported 'Firm' with a firmer 'Ultra-Firm' flip side
One of the very few firm-tier mattresses with an actual published ILD number for both major foam layers, not just a marketing label.
Best for: Stomach sleepers, heavier-body-weight sleepers, or anyone who specifically wants a verifiable firm spec rather than a brand's subjective 'firm' claim
Watch out: All-foam construction sleeps warmer than a coil-based firm mattress, and the flippable dual-firmness design means the 'other side' is even firmer than most shoppers expect from the word 'firm.'
Check price on AmazonZinus 12" Green Tea Memory Foam
All memory-foam construction, self-reported 'Medium Firm' to 'Firm' depending on the specific Zinus line, ~2.5 in comfort layer, ILD not disclosed
One of the lowest-cost ways to get a firmer all-foam feel, widely available and simple to size-swap.
Best for: Budget buyers who want a firmer feel and don't need a coil support core
Watch out: No ILD or layer-thickness verification beyond the brand's own listing copy, and budget all-foam construction typically breaks in (softens) faster over the first year than pricier foams.
Check price on AmazonWhich should you buy?
You want a checkable spec: Brooklyn Bedding Signature Hybrid, or Plank Firm.
Side sleeper, lighter build: soft to medium — Saatva Classic Plush Soft.
Back sleeper: medium to medium-firm — Avocado Green.
Stomach sleeper: medium-firm to firm — Saatva Classic Firm or Plank.
Over ~230 lb: size up in firmness; the label will feel softer than it
reads.
You want targeted relief without deep sink: the Purple grid.
Never buy on: a cross-brand comparison of "1–10" numbers — they measure
nothing in common.
This page covers mattress construction and firmness measurement. It is general equipment-fit information, not medical advice — consult a clinician for any back-pain or sleep-health concern.
Frequently Asked Questions
If you want a firmness claim you can actually verify, Brooklyn Bedding is the pick — the Signature Hybrid publishes ILD figures for multiple internal layers and the Plank Firm publishes them for both major foam layers, which almost no competitor does. For a soft innerspring, the Saatva Classic Plush Soft. For natural latex, the Avocado Green Mattress. For firm with coil support, the Saatva Classic Firm. Just remember every brand's own 1-10 number is self-assigned.
Within that one brand's lineup, and nowhere else. A brand's 1-10 firmness number or Soft, Medium and Firm label is entirely self-assigned — there is no industry body auditing it, no standard scale it is measured against, and no requirement that a 6 from one brand feel anything like a 6 from another. Two medium-firm mattresses from different brands can differ enormously in actual feel. Treat every number as a claim within that brand's own range rather than a cross-brand measurement.
Indentation Load Deflection is a defined foam-industry test: the force in pounds needed to compress a standard 15 by 15 by 4-inch foam sample by 25 percent of its thickness using a 50-square-inch circular indenter, under ASTM D3574 for polyurethane foam, with latex commonly tested under a related but distinct protocol. Higher ILD means firmer foam. The catch is that almost no mattress brand publishes it — and since it is a verifiable number a buyer could use to compare brands directly, that absence is itself the story.
Because nothing requires them to be. A self-reported label costs a brand nothing and cannot be checked, while a published ILD figure is a number a shopper could hold against a competitor. The brands that do publish ILD, such as Brooklyn Bedding, generally do so because they also sell raw foam or components to a more technical audience — not because of any industry requirement. It is worth being fair about this: the absence of ILD does not mean a mattress is low quality. It means the firmness claim cannot be independently verified.
Substantially, because a heavier body compresses further into any given foam before reaching equilibrium. A lighter sleeper, under roughly 130 pounds, sits nearer the top of a comfort layer and feels its true surface firmness. A heavier sleeper, over roughly 230 pounds, compresses through the comfort layer into the firmer support core beneath, so the same mattress can feel noticeably softer to them than the label suggests. This is why any firmness guide that ignores body weight is incomplete.
Yes, and that is why ILD is only directly comparable within similar constructions. Memory foam has a slow, viscoelastic recovery that deepens the sink-in feeling at a given ILD. Latex responds quickly and feels more buoyant at a comparable ILD. A hybrid's coil support core adds bounce and can make a soft comfort layer feel more supportive than the same foam over an all-foam base. A 28-ILD latex layer and a 28-ILD memory-foam layer will not feel the same.
Generally a softer comfort layer — roughly the self-reported soft to medium range — so the shoulder and hip can sink in enough to keep the spine level. Back sleepers usually do best in medium to medium-firm, balancing cushioning against enough support to stop the hips sinking too far. Stomach sleepers typically want medium-firm to firm so the midsection does not sink and pull the lower back out of alignment. These are general equipment-fit guidelines, not medical advice — consult a clinician for any back-pain concern.
Because ILD genuinely does not apply to their comfort layers. Purple uses a hyper-elastic polymer grid rather than foam, and it buckles under pressure points while staying firmer under lighter-loaded areas, which behaves differently from a uniform-ILD foam layer. Tempur-Pedic uses a proprietary viscoelastic material that is not standard polyurethane foam and is pressure- and temperature-responsive in ways PU foam is not. Any "ILD equivalent" quoted for either is not a real figure, so this is a legitimate non-disclosure rather than an evasion.