---
title: "Firm vs Medium-Firm Mattress: Key Differences | BedGuide"
description: "Firm vs medium-firm mattress: the 1–10 firmness scale, surface feel, body weight, sleep position, toppers and how to compare mattress firmness."
url: "https://bedguide.co.uk/compare/firm-vs-medium-firm-mattress/"
---

mattresses comparison

#  Firm vs Medium-firm

Evergreen URL: /compare/firm-vs-medium-firm-mattress

In short

  A firm mattress lets you sink very little, so you lie more on top of it. A medium-firm mattress has some give on top and firmer support below. Many UK shops put firm at about 8–9 and medium-firm at about 6–7 on a 1–10 scale, but each shop’s scale differs. Compare within one shop.

     Firm

    Medium-firm

This comparison is about mattress feel, not health. Firmness is a comfort preference. Body weight and sleep position change how firm the same mattress feels to you.

##
What is the difference between Firm and Medium-firm?

  A firm mattress lets you sink very little, so you lie more on top of it. A medium-firm mattress has some give on top and firmer support below. Many UK shops put firm at about 8–9 and medium-firm at about 6–7 on a 1–10 scale, but each shop’s scale differs. Compare within one shop.

| Criterion | Firm | Medium-firm |
| --- | --- | --- |
| Typical scale number | About 8–9 out of 10 | About 6–7 out of 10 |
| Surface feel | Little sink; you lie on top | Some sink at shoulders and hips |
| Body weight | Lighter people sink less, so it can feel very firm | Heavier people sink more, so it can feel softer |
| Sleep position (comfort) | Often chosen by back and stomach sleepers who want little sink | A common middle choice for back and combination sleepers |
| How it is built | Firmer springs or denser foam, thinner comfort layers | Medium-tension springs or foam with a thicker comfort layer |
| Changing the feel | A soft topper can soften the top | A topper can change the top feel a little |

##
Who is Firm for — and who should skip it?

- You like to lie on top of the mattress rather than in it
- You mostly sleep on your back or front
- Softer mattresses have felt too sinking for you

  [Full Firm guide →](/mattresses/mattress-firmness-scale/)

##
Who is Medium-firm for — and who should skip it?

- You want some cushioning with steady support
- You change position during the night
- Firm mattresses have felt too hard at the shoulders and hips

  [Full Medium-firm guide →](/mattresses/firmness-and-sleep-position/)

##
Frequently asked questions

###  What number is a firm mattress?
  Many shops put firm at about 8 or 9 on a 1–10 scale and medium-firm at 6 or 7. There is no UK standard, so compare scales within the same shop.

###  Can I make a firm mattress softer?
  A soft topper can change the top feel. It cannot change the support underneath. If the mattress is far too firm, check the shop’s trial or returns terms.

###  Do mattresses get softer over time?
  Comfort layers often settle a little in the first weeks, so a mattress can feel slightly softer. Deep dips are different and may be a warranty issue.

   **Educational comparison only.**
This comparison does not recommend brands, and payment never changes it.
      Last reviewed 2026-10-21.

  [← All comparisons](/compare/)

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Source: https://bedguide.co.uk/compare/firm-vs-medium-firm-mattress/ · BedGuide — independent UK bed guide; paid links are labelled (see /how-we-make-money/). See https://bedguide.co.uk/editorial-policy · Report an error: https://bedguide.co.uk/corrections.