Why do mattress reviews say the same bed is too firm and too soft?

This confusion is common enough that some shoppers end up writing reviews just to referee it — long posts walking future buyers through why the “too soft” camp and the “too firm” camp are both telling the truth. They’re onto something. Here’s what’s actually going on.

Firmness is measured by the body reading it

A mattress doesn’t have one feel; it has a response. How much of that response you experience depends first on body weight and sleeping position. A lighter side sleeper may never compress a firm comfort layer enough for it to give around the shoulder and hip, so the surface can feel hard against the areas that need more give — that bed gets described as sleeping on the floor. A heavier back sleeper on the same model may press farther through the comfort layer; if the bed allows more settling than expected, the same mattress can be described as too soft — or, in the more vivid reports, as sleeping in a hammock. Neither review is wrong. They’re measurements taken with two different instruments.

Same name, different beds

Most review sections pool more than one version of a product: different thicknesses, different firmness options, different sizes, and sometimes quietly revised builds. A thicker version with a deeper comfort layer and a thinner version under the same product name can feel meaningfully different on night one — and can age differently, too. Listings also tend to live longer than builds: a product name can span several generations, and its review section keeps collecting opinions about versions that may no longer ship. Some long-running listings even accumulate reviews from repeat buyers noting that a replacement unit didn’t feel like the one it replaced. None of this tells you how a specific unit will behave — but it’s one more reason two honest reviews can be describing two genuinely different beds. Before treating any review as evidence, check whether it’s talking about the variant, and roughly the era, of the product you’re actually considering.

Everyone is comparing against a different bed

Firmness labels are comparative, not universal. A shopper coming off a decade-old innerspring and a shopper coming off a plush pillow-top will file the same medium-firm surface under opposite categories, because each is describing the change, not the mattress. “Medium-firm” tells you where a bed sits in a brand’s own lineup; it doesn’t tell you how it will feel against your reference point.

“Soft on top but hard underneath” — and its mirror image

Some reviewers report both sensations at once: a soft surface over a hard core. That’s often an accurate reading of the construction — a plush comfort layer resting on a firm support system — and whether the combination feels right depends on how far your body presses through the soft part. Other reviewers flip it around: firm but not supportive, a surface that feels hard while the hips still settle too far by morning. That’s a report about two layers as well, just with the roles reversed. Both phrasings point to the same lesson: firmness is the resistance you feel as the mattress compresses, while support is how the full structure manages your weight and controls settling under load — related, but not the same, and worth evaluating separately. Our guide to what support actually means draws that line in full.

What reviews can’t settle

Review text alone can’t tell you why a specific unit disappointed. A complaint might trace to a different variant, a bed that never fully recovered from packaging, a foundation problem, a revised build, or the design itself — and no amount of reading distinguishes those from the outside. That’s a limit worth respecting in both directions: reviews are excellent at surfacing patterns and language, and weak at assigning causes.

How to find the reviews that matter for you

Look for reviewers who share your build and sleeping position, bought the variant you’re considering, and used the bed nightly rather than occasionally. Give the most weight to reviews updated after months of use — first-week impressions describe the surface, long-term updates describe the structure. And when a review mentions what foundation the bed sat on, treat that as valuable context. We keep a full checklist in our guide to reading reviews and warranties.