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Mattress Firmness Guide
Updated January 2026
Choosing the right level of mattress firmness is one of the most important decisions you’ll make when buying a new mattress – and one of the most confusing. Firmness ratings aren’t standardised across the industry, and what feels “firm” to one person may feel uncomfortable to another.
This guide explains what mattress firmness really means, how to understand the 1 to 6 firmness scale that we use here at The Bed Specialist, and how to choose the right firmness level based on your body, sleep position, and comfort preferences.
Nick has over twenty years experience in the bed and mattress industry; he sums up the different firmness grades on offer in this short video:
What is mattress firmness?
Mattress firmness describes how soft or firm a mattress feels when you lie on it, particularly how much your body sinks into the surface. It is not the same as support.
- Firmness – How the surface of a mattress and its comfort layers feel when you lie down, whether if feels soft, firm, or somewhere in between.
- Support – This is about a mattress’s inner core structure and your spinal alignment, and how evenly your weight is distributed to prevent body sag or bowing.
A mattress can feel soft but still be supportive, or firm but poorly supportive, which is why firmness alone shouldn’t be your only consideration. Getting the right balance will help to improve your quality of sleep and avoid long-term aches and pains that arise from poor mattress support.
Understanding the 1 to 6 mattress firmness scale
At The Bed Specialist, mattresses are rated on a 1 to 6 firmness scale, with 1 being the softest and 6 being the firmest. This scale is used consistently across all our products, making it easier to compare options.
| Firmness Rating | Feel | Who It's Genreally Best For |
|---|---|---|
| 1 - Soft | Very plush, deep sink | Very light sleepers, side sleepers who like a soft feel |
| 2 - Soft / Medium | Soft with gentle support | Side sleepers, lighter-weight sleepers |
| 3 - Medium | Balanced comfort and support | Combination sleepers, average-weight sleepers |
| 4 - Medium / Firm | Supportive with moderate cushioning | Back sleepers, mixed sleep positions |
| 5 - Firm | Minimal sink, strong support | Back and stomach sleepers, heavier sleepers |
| 6 - Extra Firm | Very firm, flat feel | Back and stomach sleepers, those over 20 stone or who prefer very firm beds |
This scale provides a useful reference point, but personal comfort will still vary based on body weight, sleeping position, and mattress materials. Here’s more detail about each firmness grade on the scale:
1. Soft comfort mattresses
Soft mattresses are the most cushioned option on the firmness scale, designed to provide a plush, contouring feel. They allow the body to sink into the mattress rather than resting on top, which can help relieve pressure across the shoulders and hips.
Typically best suited to lighter sleepers (around 12 stone or less), soft mattresses combine gentle surface comfort with responsive support from the core. Construction quality is especially important at this firmness level, as a well-built mattress is better able to maintain consistent comfort and shape over time. One mattress brand that consistently stands head and shoulders above others for reliable build quality is Vispring.
2. Soft-to-medium feel mattresses
Soft-to-medium mattresses offer great cushioning while still providing supportive comfort, making them particularly suitable for side sleepers. This firmness helps relieve pressure at key contact points such as the hips and shoulders, which bear more load when sleeping on your side.
Generally recommended for sleepers up to around 12 stone, soft-to-medium feel mattresses should benefit from strong internal construction to maintain support over time. Longevity is linked to build quality: look for hand-stitched borders and top-grade pocket spring wires to ensure the mattress performs consistently, while also keeping its softer, more forgiving feel.
3. Medium tension mattresses
A firm favourite the length and breadth of the UK, medium comfort grade mattresses offer a combination of cushioning and support that suits a wide range of sleepers. The core of the mattress is responsive, with enough surface comfort to avoid feeling too firm.
The level of cushioning and edge support can vary depending on construction quality, but overall, this firmness aims to deliver adaptable comfort that responds well to body movement, while still offering stable support throughout the night.
4. Medium / firm graded mattress
Medium-to-firm mattresses provide a stable sleeping surface with a slightly firmer feel, making them well suited to people who shift position more often. The firmer surface helps you move around more easily, while still offering cushioning and responsive support from the mattress’s core.
Customers often choose this firmness level for its dependable feel, particularly in simpler constructions, where a more stable core and edge support can contribute to a supportive and consistent sleeping experience.
5. Firm mattresses
Firm mattresses are typically recommended for back and stomach sleepers, or for heavier sleepers weighing between 16 and 20 stone, who require stronger surface support to maintain spinal alignment.
Customers often find that their new mattress feels firmer at first, but softens slightly over time as both the mattress and sleeper adjust – it might take about three months before you begin to feel fully supported and comfortable.
Top Tip - Consider a comfort grade one level softer than you think you might need. In our experience, the most common mistake that a customer makes is buying a mattress that’s too firm for their needs.
6. Extra-firm-rated mattresses
Extra firm mattresses provide the most rigid sleeping surface on the firmness scale. They provide a flat, supportive surface with minimal cushioning and maximum stability, no matter the construction type. They are generally suited to back and stomach sleepers who prefer a very firm feel, as well as heavier individuals in excess of 20 stone.
How sleeping position affects firmness choice
Your primary sleeping position plays a major role in determining the right firmness.
Side Sleepers
Side sleepers typically need more pressure relief at the shoulders and hips.
- Recommended firmness: 1–3
- Too firm can cause pressure points and discomfort
Back Sleepers
Back sleepers usually benefit from a balanced feel that supports the lower back without excessive sink.
- Recommended firmness: 3–5
Stomach Sleepers
Stomach sleepers need a firmer surface to prevent the hips from sinking too far and straining the spine.
- Recommended firmness: 4–6
Body weight and mattress firmness
Body weight affects how much pressure you place on a mattress:
- Lighter sleepers often find firm mattresses feel harder than expected and may prefer softer ratings (1–3)
- Average-weight sleepers typically find comfort in the 3–4 range
- Heavier sleepers may need 5–6 firmness to maintain proper spinal alignment
Common misconceptions about mattress firmness
“A firmer mattress is always better for your back”
Not necessarily. Back support comes from proper spinal alignment, not surface hardness. For many people, a medium or medium-firm mattress provides better long-term comfort.
“Firmness ratings are the same everywhere”
They aren’t. A “medium” mattress from one brand may feel firmer or softer than another, which is why understanding a retailer’s internal scale is helpful.
How long does it take to adjust to a new mattress?
New mattresses often feel firmer than expected at first. This is quite normal!
- Most mattresses require up to three months to break in
- Your body also needs time to adjust to a new sleep surface
Give your new mattress a chance before deciding to return it. It’s a big investment, so we understand this can cause some anxiety. That’s why we offer a 100-night mattress comfort trial (conditions apply).
Mattress firmness vs mattress type
The materials used also influence how firmness feels:
- Memory foam often feels softer due to contouring
- Pocket sprung mattresses tend to feel firmer and more responsive
- Hybrid mattresses combine cushioning and support, often balancing firmness well
Two mattresses with the same firmness rating can feel different depending on construction.
Mattress examples with different firmness ratings
If you’d like to see how firmness ratings translate into real products, the following examples illustrate mattresses we have available at each firmness level:
| Firmess Rating | Great Value | Handmade Mide-Level Receommendation | Luxury Handmade Artisan |
|---|---|---|---|
| 1 - Soft | Sleepeezee G Memory Foam Mattress | Enchanted House Cheldon Mattress | Vispring Shetland Mattress |
| 2 - Soft / Medium | Luna Wellbeing 1000 pocket mattress | Hypnos Blenheim Mattress | Vispring Dartington Mattress |
| 3 - Medium | Sleepeezee Wool Superb 2800 Mattress | Enchanted House Marldon Mattress | Vispring Kingsbridge Mattress |
| 4 - Medium / Firm | Luna Immerse Quilt 1000 Mattress | Dunlopillo Elite Luxury Latex Mattress | Enchanted House Superb Pillow Top Mattress |
| 5 - Firm | Hypnos Posturecare 6 Mattress | Enchanted House Serene Pillow Top Mattress | Vispring Regal Superb Mattress |
| 6 - Extra Firm | Sleepeezee Ortho Bespoke Silver 1600 Mattress | Luna Support Orthos 2000 Mattress | Enchanted House Holcombe Mattress |
Top Tip - Visit a showroom to test any mattress you’re considering buying. Not all comfort grades feel the same – different bed brands, upholstery levels and pocket spring numbers create subtle differences with every option.
Final thoughts: choosing the right firmness
There’s no universally “correct” mattress firmness, only what’s right for your body, sleep position, and comfort preferences.
When choosing firmness:
- Use the 1 to 6 scale here as a guide
- Consider your sleeping position and body weight
- Allow time to adjust to a new mattress
Our friendly bed specialists can advise and guide you through every option as you consider your ideal mattress or divan.
Visit our lovely Yeovil showroom to try our mattresses for yourself, or call us on 01935 423596.
Category: Mattress Guides
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