Mattress comfort scales indicate how firm the mattress is, and you can use them as benchmarks when shopping for mattresses.
A comfortable mattress makes a world of difference in getting a good night’s sleep. If you toss and turn and struggle to settle down in bed, it’s probably because your mattress is either too soft or firm.
Choosing the correct mattress firmness is critical to comfort, and the proper firmness rating depends on how you sleep (sleeping position) and your body weight.
The mattress industry rates mattresses on a “firmness scale,” sometimes visualised with a range from 1-10, with ‘1’ the softest and ‘10’ the firmest.
Here’s what the comfort scale looks like:
- 1-2 – soft. No adult mattresses on the market are rated this low, making it a pseudo rating. Such a mattress would be so weak that it would crumple under you.
- 3-5 – medium-soft. These mattresses are best for lightweight people (under 130lbs) and those who want a cloud-like sleep.
- 6-7 – medium. The most versatile of all mattress grades, medium mattresses are best for side and occasional back sleepers.
- 8-9 – medium-firm. Medium-firm mattresses are best for back sleepers and are suited to heavier people.
- 9-10 – firm. Also known as orthopaedic mattresses, these have little give, suiting front sleepers and heavy people.
Some manufacturers don’t use the point scoring system and only label their mattresses, but you can use the guide above to translate things.
Firmness is relative
Despite the comfort scale above being helpful, there is a fly in the ointment.
That fly in the ointment is that firmness is relative, so firm mattresses are soft to heavy people, and medium mattresses are firm to lighter people.
Simply put – the heavier you are, the softer a mattress feels, meaning you need to go up the scale the heavier you are.
Here’s what we recommend:
- Over 230 lbs – firm
- Over 190 lbs – medium-firm
- Over 130 lbs – medium
- Over 110 lbs – medium-soft
For most people, a medium or medium-firm mattress is best – this is a matter of providing the best possible support for your body weight.
Another way to choose a mattress is based on your sleeping position.
- Back sleepers do best with a medium-firm mattress due to the extra support provided across the sleep surface.
- Side sleepers do best with a medium mattress unless they are over 200lbs, in which case a medium-firm mattress is best.
- Front sleepers always do best with a firm mattress to keep the spine in a neutral position.
- We recommend a medium mattress for optimal comfort if you fall within the 140 lb to 190 lb range and sleep in multiple positions.
- If you sleep with chronic pain, a softer mattress will help if your pain is muscular, while a firmer mattress will help if your pain is musculoskeletal.
Firmness denotes support – not comfort!
A common misconception about the firmness scale is that it denotes how comfortable, squishy, or flexible a mattress is. This is not true! Firmness suggests a mattress’s support, i.e., how much it will compress under the body.
For example, a medium-firm mattress with a thick, 5cm layer of memory foam (such as the Mlily Bamboo Superb) feels super-soft when you lie on it. Still, the firmer support system gives you excellent rigidity to support your spine.
Pictured: Mlily Bamboo Superb, bamboo charcoal-infused memory foam mattress. Available from Bedstar. The Online Bed Superstore.
The goal when choosing a mattress is to support natural sleeping posture, where your spine has a subtle curve and aligns with your hips and head.
Mattress thickness also matters for comfort.
While a mattress’s comfort/firmness rating is essential, its thickness also plays a fundamental role in how it feels.
Thin mattresses travel less, so the heavier you are, the worse they sleep. Softer mattresses also need to be thicker than firmer models due to the extra compression they experience when you lie on them. Most mattresses are 25cm to 30cm thick, with medium-soft mattresses leaning towards the top of the scale.
Our article covering mattress thickness reveals more information, including how technology and construction play a role in mattress comfort.