Mattress Firmness by Weight: Reference Table (2026)
Partilhar
The question I get asked most on the phone is "what's the right firmness?" The honest answer is that it depends mainly on two things: how much you weigh and what position you sleep in. This article gives you the table I use in consultations, with the numbers behind it.
Why weight decides almost everything
A mattress works through sinkage. Your body sinks into the surface until it finds support, and what determines the depth of that sinkage is the pressure you exert per square centimetre — in other words, your weight distributed across your contact area.
That's why the same mattress can feel "hard" to a 55 kg person and "soft" to a 100 kg person. Neither is wrong. They are feeling the same surface respond differently to each person's weight.
That's also why the label isn't enough. "Medium firmness" is each manufacturer's internal scale, not a standardised measure. What can be compared rigorously is foam density and type of support.
Table: recommended firmness by weight
This is the reference I use. It applies to one adult, per person, and assumes you sleep in a mix of positions.
| Weight | Recommended firmness | Minimum foam density | Structure I usually suggest |
|---|---|---|---|
| Up to 60 kg | Medium to medium-soft | 30–35 kg/m³ | High-resilience foam or springs with comfort layer |
| 60–90 kg | Medium to medium-high | 35–40 kg/m³ | Pocket springs with memory foam |
| 90–110 kg | Medium-high to high | 40 kg/m³ or more | Pocket springs with reinforced high-resilience foam |
| Above 110 kg | High | 40 kg/m³ or more | Pocket springs, height from 24 cm |
Body height slightly adjusts these values. If you are tall and lean, your weight is distributed over a larger area and you can go down half a point in firmness. If you are short with the same weight, go up half a point.
Density: the number you're rarely given
Density is measured in kilograms per cubic metre and tells you how much material there is inside the foam. It is the best single indicator of how long a mattress will last.
- Below 25 kg/m³ — low-density foam. Loses its shape within a few years, especially under weights above 80 kg.
- 25 to 30 kg/m³ — acceptable for occasional-use beds, guest rooms or low-turnover short-term rentals.
- 30 to 40 kg/m³ — the daily-use range. This is where the mattress you sleep on every night should sit.
- Above 40 kg/m³ — recommended above 90 kg, or for those who want greater longevity.
If a product sheet doesn't state the density, ask. If they don't answer with a number, that in itself is an answer.
The position you sleep in adjusts the recommendation
After setting firmness by weight, adjust it by position:
- Side sleeping — go down half a point. The shoulder and hip need to sink in for the spine to stay straight. A mattress that is too firm will leave you with shoulder pain after a few weeks.
- Back sleeping — stay at the table's firmness. You need continuous lower-back support, without letting the pelvis drop.
- Front sleeping — go up half a point. If the pelvis sinks, the lower back arches and you wake up in pain.
If you're not sure which position you spend most time in, see best position for sleeping.
Couples with very different weights
This is the most common case I hear about — and it has a solution without needing two beds.
If the weight difference between the two of you is less than 25 kg, choose based on the average of both weights and use pocket springs, which work independently and don't transmit movement from one side to the other.
If the difference is more than 25 kg, my suggestion is to choose the firmness for the heavier person and soften the lighter person's side with a mattress topper. A mattress that's too firm can be corrected with a layer on top; a mattress that's too soft can't be corrected with anything.
This is the most useful rule in the whole article: when in doubt, choose the firmer of the two. I went deeper into this in mattress for couples with different preferences.
What I suggest by weight range
| Profile | Dreamura model | Why |
|---|---|---|
| Up to 60 kg, side sleeper | Sora (空) | Springs and high-resilience foam, medium firmness, lets the shoulder sink in |
| 60–90 kg, mixed positions | Takumi (匠) | Pocket springs, memory foam and high-resilience foam. 26 cm, medium firmness |
| 60–90 kg, back sleeper with lower back pain | Hisui (翡翠) | High-resilience foam with memory foam, firm, 26 cm |
| 90–110 kg | Mizu (水) or Samurai (侍) | High firmness with continuous support and good ventilation |
| Above 110 kg | Samurai (侍) or Shinobi | Pocket springs with reinforced high-resilience foam |
You can see all of them at mattress range or compare the three spring models at Takumi vs Mizu vs Sora.
How to know if you got it right
Lie on your back and slide your hand under your lower back. If your hand slides in easily, the mattress is too firm for you. If you can't fit your hand in, it's too soft. If it goes in with slight resistance, it's right.
After that, give your body time. Allow 14 to 21 nights of adaptation — it's normal for the first ones to feel strange, even with the right choice. After 21 nights, if you wake up with stiffness in your lower back, the firmness is too high. If you wake up with a "trench" feeling in the middle, it's too low.
This is exactly what the 100-night trial is for: to decide with your body, not with five minutes in a store. See how the 100 nights work.
Questions I get asked
I lost 15 kg. Do I need to change my mattress? Not necessarily. A variation of up to 15 kg usually stays within the same range. Reassess if you move to another row of the table.
I'm pregnant. Does anything change? It does. Weight goes up and the position shifts to mostly left-side sleeping. I wrote a dedicated guide: mattress and sleep during pregnancy.
Is a harder mattress better for your back? No. It's the most persistent myth I hear. The evidence points to medium firmness as giving the most relief for chronic lower back pain. See hard or soft mattress for your back.
Does a mattress topper fix the wrong mattress? It softens a mattress that's too firm. It doesn't harden a mattress that's too soft, nor does it fix a sagging mattress.
"If you can only keep one number from this article, keep the density: 35 kg/m³ for daily use, 40 kg/m³ above 90 kilos. It decides more than any adjective on the label." — Ana Cristina, Sleep Advisor
If you have chronic pain, a herniated disc or another diagnosed condition, talk to your doctor or physiotherapist before deciding. This table is a starting point, not a substitute for clinical assessment.
How to decide
Weigh yourself. Identify the position you spend the most time in. Cross the two in the table. Confirm the density with the seller. Only then look at the price.
If you want to skip ahead, take the mattress quiz or call me on +351 21 150 95 04. We'll get there in 10 minutes.
