by The mattress firmness scale runs 1-10, but there is no industry standard, so a "6" from Brand A may feel different from a "6" from Brand B. Most sleepers land between 5 and 7. Our top pick for the firmness sweet spot is the Saatva Classic, which publishes three clearly-differentiated tiers (Plush Soft ~4, Luxury Firm ~6.5, Firm ~8), making it the clearest reference mattress on the market. The Amerisleep AS3 is the strongest single-firmness foam pick at medium 5/10.
Saatva Classic
9.2/10
- Three published firmness options (Plush Soft ~4, Luxury Firm ~6.5, Firm ~8) covering every major sleep position
- Dual-coil construction with zoned lumbar pad and outstanding edge support
- 365-night home trial, lifetime warranty, free white-glove delivery and old-mattress removal
- Zero off-gassing, ships uncompressed and set up in your room
- $99 return fee during trial
- Heavy, not roll-packed, harder to reposition alone
If you are unsure of your firmness number, the Saatva Classic is the best test case because it publishes three clearly-differentiated options at real prices. Luxury Firm (6.5) covers most back and combo sleepers; Plush Soft (4) suits side sleepers under 150 lb; Firm (8) is right for stomach sleepers and heavier frames. No other mattress at this price gives you that range with a 365-night trial.
Amerisleep AS3
9.0/10
- Medium 5/10 is the most universally effective firmness for back, side, and combo sleepers 130-230 lb
- HIVE 5-zone layer adjusts firmness by body zone, not just overall
- Plant-based Bio-Pur foam runs cooler than standard memory foam
- CertiPUR-US certified, made in the USA, 100-night trial and 20-year warranty
- Softer edges than a coil hybrid
- Sleepers over 230 lb may need the firmer AS5 Hybrid instead
The AS3 sits at medium 5/10, the sweet spot where side and back sleeper ranges overlap. If you have already decided on a single medium-firmness foam mattress and want zoned support without an innerspring, this is the strongest all-foam pick.
The problem with the 1-10 firmness scale
The mattress industry uses a 1-10 firmness scale as if it is an objective standard. It is not. There is no industry body that certifies firmness ratings, no standardized testing protocol all brands follow, and no shared calibration method. A mattress rated "7 out of 10" from Brand A may feel softer or firmer than a "6" from Brand B.
This is not brand deception, it is an inherent limitation of trying to quantify subjective tactile experience without universal standards. The scale is still useful as a within-brand comparison tool and as a rough cross-brand guide, but it requires context to use effectively.
What the numbers typically mean
| Rating | Common label | Saatva Classic option | Best for |
|---|---|---|---|
| 1-2 | Ultra Soft | - | Near-zero practical use; specialty medical applications |
| 3-4 | Soft / Plush | Plush Soft (~4) | Lightweight side sleepers (under 130 lb) |
| 5-6 | Medium / Medium-Soft | - | Most side sleepers, combo sleepers 130-230 lb |
| 6-7 | Medium-Firm / Luxury Firm | Luxury Firm (~6.5) | Back sleepers, combo sleepers 130-230 lb |
| 7-8 | Firm | Firm (~8) | Back and stomach sleepers, sleepers over 230 lb |
| 9-10 | Extra Firm | - | Very heavy sleepers, certain therapeutic use |
Body weight changes what the scale means for you
This is the most important calibration factor that most buyer guides underemphasize. A "medium-firm 6.5" mattress performs very differently depending on the person:
- A 120-lb side sleeper on a 6.5 rating will experience it as firm, because their lighter weight does not compress the comfort layers enough for pressure relief.
- A 180-lb side sleeper on the same mattress will likely feel it as intended, medium-firm with adequate hip and shoulder give.
- A 260-lb back sleeper will compress much deeper, making the same 6.5 feel more like a 5, which can cause lumbar sag.
The practical adjustment: lighter sleepers under 130 lb should target 1-1.5 numbers softer than their intended feel. Heavier sleepers over 230 lb should target 1-1.5 numbers firmer.
Verbal labels are even less standardized than numbers
One brand's "Plush" may be a 4; another's may be a 5.5. "Luxury Firm," a term Saatva uses, typically means 6-6.5 on the universal scale, but the label alone is meaningless without a reference number. When evaluating verbal labels, always ask what the equivalent is on a 1-10 scale, or check independent reviews where testers compare against a calibrated reference point.
How firmness changes over time
Mattresses do not maintain their initial rating indefinitely. Comfort layers compress over the first 30-90 days of use, which is normal. A new "7" may feel closer to a "6.5" after 60 days of regular use.
After that break-in period, quality mattresses hold their feel reasonably well within their rated lifespan. Budget foam mattresses starting at "6" may effectively feel like a "4" within three years as low-density foam degrades. Higher foam density is the primary factor in long-term firmness retention.
The three firmness tiers that cover most sleepers
In practice, most people fall into one of three categories:
- Side sleepers: 4-6 (soft to medium) for most body weights. Softer for lightweight, firmer for heavier frames.
- Back sleepers: 5.5-7 (medium to firm). The lumbar needs enough firmness to prevent sag, but enough cushion for the natural lordotic curve to settle.
- Stomach sleepers: 6-8 (medium-firm to firm). Soft mattresses cause lumbar hyperextension face-down, which is hard on the lower back.
The Saatva Classic covers all three tiers with its published firmness options, which is why it is the most comprehensive single-brand reference for the firmness scale. The Amerisleep AS3 at medium 5/10 sits where side and back sleeper ranges overlap, making it the strongest single-firmness foam pick for combo sleepers.
Saatva Classic firmness options at a glance
| Option | Firmness approx. | Best for |
|---|---|---|
| Plush Soft | ~4 (Soft) | Side sleepers under 150 lb, pressure sensitivity |
| Luxury Firm | ~6.5 (Medium-Firm) | Back and combo sleepers 130-230 lb, most popular |
| Firm | ~8 (Firm) | Stomach sleepers, heavier frames over 230 lb |
Amerisleep firmness lineup at a glance
| Model | Firmness approx. | Best for |
|---|---|---|
| AS1 | ~8-9 (Very Firm) | Stomach sleepers, heavy frames |
| AS2 | ~6.5-7.5 (Medium-Firm) | Back and stomach sleepers 130-230 lb |
| AS3 | ~5.5-6.5 (Medium) | Side, back, and combo sleepers, best-seller |
| AS4 | ~4 (Medium-Soft) | Side sleepers under 150 lb |
| AS5 | ~3-4 (Plush) | Lightweight side sleepers, pressure conditions |
Firmness ratings for Amerisleep are aggregated from independent reviews, as the brand does not publish official numeric ratings. Actual perceived firmness varies by body weight as described above.
The firmness scale is a useful starting point, not a precise specification. Medium (5-6) is where most sleepers land. The Saatva Classic is our top pick because it covers all three primary firmness tiers with a 365-night trial, and the Amerisleep AS3 is the best single medium-firmness foam pick if you have already narrowed down to all-foam.
Frequently asked questions
Is the 1-10 mattress firmness scale standardized?
No. There is no industry body that certifies firmness ratings. A "7" from one brand may feel different from a "7" from another. The scale is most useful for within-brand comparisons.
What firmness number is best for back pain?
Medium-firm 6-7 is the most commonly recommended range for back sleepers. For a position-specific breakdown see our back pain mattress guide.
What does medium-firm mean on the 1-10 scale?
Typically 6-7, though this varies by brand. It is the most popular range for back sleepers and combination sleepers in the 130-230 lb weight range.
Should heavier people buy a firmer mattress?
Generally yes. Heavier sleepers over 230 lb compress mattresses more deeply, so shopping 1-1.5 numbers firmer than your target feel compensates for that deeper compression.
What is Luxury Firm on the mattress firmness scale?
Approximately 6.5 on the universal scale, a medium-firm feel appropriate for most back sleepers and combination sleepers in the 130-230 lb range. It is the most popular option in the Saatva Classic lineup.