Made in Britain
Firm mattresses
A firm mattress, graded 9 to 10 on our 1 to 10 scale, has very little give, so you lie on top of it rather than in it. It suits front sleepers, heavier people and anyone who likes a solid feel.
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What is a firm mattress?
A firm mattress is one with very little give at the surface, graded 9 to 10 on our 1 to 10 firmness scale, so your body rests on top of it instead of sinking in.
The feel comes from a strong support core with thin or firm comfort layers above it: pocket or open coil springs under a firm top, or dense reflex foam. Mattresses sold as extra firm sit at the top of this band. Some people call a firm mattress a hard mattress, but it usually still has a thin layer of cushioning on top; it just won't let you sink into it.
Brands grade firmness differently, so one maker's firm can feel like another's medium-firm. Go by our number rather than the label on your old mattress.
Who should sleep on a firm mattress?
Firm mattresses (9 to 10) suit front sleepers and heavier people, who both need a surface that stops the hips sinking, and anyone who simply prefers lying on top of a mattress rather than in it.
| Sleeper | Medium-firm (7 to 8) | Firm (9 to 10) |
|---|---|---|
| Front sleeper | Good fit, especially if lighter | Good fit, especially if heavier |
| Back sleeper | Good fit | Suits heavier back sleepers |
| Side sleeper | Can suit heavier side sleepers | Usually too firm |
| Heavier build | Good fit | Good fit |
| Lighter adult or child | Can feel firm | Often feels hard |
Front sleepers need their hips held level so the lower back doesn't arch, which is why our guide to mattresses for front sleepers starts at medium-firm. Heavier people press further into any mattress, so as well as firmness they usually need more depth, strong springs and firm edges; see our mattresses for heavier people. Others simply like the feel: on a firm surface it's easy to change position, and the mattress doesn't close around you.
Is a firm mattress better for your back?
A firm mattress isn't automatically better for your back: when Kovacs and colleagues compared firm and medium-firm mattresses in a 2003 trial published in The Lancet, people with chronic lower back pain did better on medium-firm.
What matters more is whether the mattress keeps your spine in line for the way you sleep. For a front sleeper or a heavier person that may well be firm; for a lighter side sleeper it rarely is. If you have back pain that doesn't go away, see a GP or physiotherapist rather than reaching for a firmer mattress, and read our page on mattresses for back pain.
Firm or orthopaedic: what's the difference?
Firm describes how a mattress feels, while orthopaedic is a label with no legal or medical definition in the UK that usually means a firmer, more supportive build.
An orthopaedic mattress might be firm (9 to 10) or medium-firm (7 to 8), and the name doesn't mean it has been medically approved. Judge any mattress by its firmness number and construction rather than its name. Our orthopaedic mattresses page explains the label in more detail.
Can a mattress be too firm?
A mattress is too firm when it won't let your shoulders and hips sink in enough for your spine to stay level, which happens most often to side sleepers, lighter adults and children on a firm (9 to 10) mattress.
Signs include pressure building at the shoulder or hip when you lie on your side, a gap under your waist or the small of your back, and shifting position through the night to get comfortable. If the mattress is otherwise in good condition, a mattress topper can soften the surface. If it's simply the wrong firmness for how you sleep, a medium-firm mattress keeps most of the support with a little more give.
Not sure whether you need firm or medium-firm? Ask us, with a note of how you sleep and what you're replacing, and we'll point you to the right band.
Firm mattresses: your questions answered
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What is an extra firm mattress?
An extra firm mattress has almost no give at all. On our 1 to 10 scale, mattresses sold as extra firm sit at the top of the firm band (9 to 10). Extra firm suits people who want a very solid surface, often heavier front or back sleepers, and is likely to feel hard to lighter people and side sleepers.
Is a firm mattress good for heavier people?
A firm mattress often suits heavier people, who press further into a mattress and usually need firmer support. Firmness isn't the whole answer: a deeper mattress, a strong spring unit and firm edges matter too, especially if you sit on the edge of the bed to get up. Heavier side sleepers may still be happier on medium-firm (7 to 8).
Will a firm mattress soften over time?
A firm mattress may feel slightly softer once its top layers settle in the first few weeks, but the change is small, so don't buy firmer than you like and expect it to wear in. Turning it head to toe regularly helps it wear evenly. A dip or lumps are wear rather than softening, and a sign it's time to replace it.
Is a firm mattress good for side sleepers?
A firm mattress is rarely right for side sleepers. At 9 to 10 on our scale it pushes back at the shoulder and hip, the two points that need to sink in for the spine to stay level. Most side sleepers do better on medium-soft to medium (3 to 6). A heavier side sleeper who likes a firmer feel could try medium-firm.
Is a firm mattress good for back sleepers?
A firm mattress suits some back sleepers, mainly heavier ones, but most do better on medium to medium-firm (5 to 8 on our scale). On a firm mattress the hips and shoulders stay on the surface, which can leave the small of the back with little underneath it.
Is sleeping on a hard mattress good for you?
Sleeping on a hard mattress is only good for you if it suits the way you sleep and your build. Front sleepers and heavier people often suit firm; side sleepers, lighter adults and children often find it uncomfortable. There's no rule that harder is healthier, and anyone with ongoing back pain should see a GP or physiotherapist.
Is a firm mattress good for children?
A firm mattress usually isn't the best choice for a child: most children sleep well on medium to medium-firm, and many find a very firm mattress hard. Babies under 12 months are the exception. The Lullaby Trust's safer sleep advice is a firm, flat, waterproof mattress that fits the cot snugly, with the baby on their back and no pillows, duvets or bumpers.
Is a firm mattress good for front sleepers?
A firm mattress suits many front sleepers, because it stops the hips sinking and the lower back arching. Front sleepers generally do best between medium-firm and firm (7 to 10 on our scale): lighter front sleepers often prefer medium-firm, heavier ones firm. Pair it with a low, soft pillow or none, so your head isn't pushed back.
Not sure which mattress?
Tell us about your bed and how you sleep, and we'll suggest a few that fit.