Best thick and deep mattresses in the UK (30cm+) (2026)
Most mattresses are 20 to 25cm deep. A deep mattress, 30cm or thicker, has room for more layers: a second layer of springs, a pillow top, or thick wool and latex. That usually means better pressure relief and edge support, and a mattress that holds its shape for longer.
These are the mattresses 30cm and deeper that scored highest in our testing. Check your fitted sheets: many standard sheets only fit mattresses up to about 30cm.
Quick answer
Of the thick and deep mattresses in the UK (30cm+) we have tested, our top pick is the Millbrook Serenity Luxury 6500 (Millbrook Beds), scoring 8.7/10 at £1,450. For the best value, the Millbrook Serenity 4500 scores 8.4/10 for value at £899. The cheapest we rate is the Luxe Nova Hybrid at £449.
| # | Mattress | Type | Firmness | Score | Price | Deal |
|---|---|---|---|---|---|---|
| 1 | Millbrook Serenity Luxury 6500Millbrook Beds · Pocket spring · Medium | Pocket spring | Medium | 8.7/10 | £1,450 | Deal |
| 2 | LuxeErgo 3400 HybridLuxe Mattresses · Hybrid · Firm | Hybrid | Firm | 8.7/10 | £464 | Deal |
| 3 | Millbrook Serenity 4500Millbrook Beds · Pocket spring · Medium | Pocket spring | Medium | 8.7/10 | £899 | Deal |
| 4 | Simba Hybrid LuxeSimba · Hybrid · Medium | Hybrid | Medium | 8.6/10 | £1,799 | Deal |
| 5 | Luxe-Latex Natural Pillow Top 5000Luxe Mattresses · Latex · Medium-firm | Latex | Medium-firm | 8.6/10 | £674 | Deal |
| 6 | Simba Hybrid UltraSimba · Hybrid · Medium-soft | Hybrid | Medium-soft | 8.5/10 | £2,399 | Deal |
| 7 | LuxeOrganic Hybrid LatexLuxe Mattresses · Latex · Medium | Latex | Medium | 8.5/10 | £471 | Deal |
| 8 | Luxe Nova HybridLuxe Mattresses · Hybrid · Medium-soft | Hybrid | Medium-soft | 8.5/10 | £449 | Deal |
Our picks in detail
Millbrook Beds
Millbrook Serenity Luxury 6500
from Millbrook Beds
Luxe Mattresses
LuxeErgo 3400 Hybrid
from Luxe Mattresses
Millbrook Beds
Millbrook Serenity 4500
from Millbrook Beds
Simba
Simba Hybrid Luxe
from Simba
Luxe Mattresses
Luxe-Latex Natural Pillow Top 5000
from Luxe Mattresses
Simba
Simba Hybrid Ultra
from Simba
Luxe Mattresses
LuxeOrganic Hybrid Latex
from Luxe Mattresses
Luxe Mattresses
Luxe Nova Hybrid
from Luxe Mattresses
How we picked
Every mattress in our catalogue at least 30cm deep, ranked by overall score. Depth alone is not quality, so a deep mattress still has to earn its place on support and comfort.
Scores are set by Alexander Bowman using the criteria on our how we score page. We may earn a commission when you buy through our links; this never affects a score or a ranking.
Not sure this is your category?
Four questions about how you sleep and your budget, and we rank every mattress we have scored against your answers.
Take the quizBest thick mattresses: frequently asked questions
Is a thicker mattress better?
Not automatically. Extra depth means more comfort layers and usually better edge support and durability, but a deep mattress with a weak core is still a poor mattress. Heavier people benefit most, because they compress the top layers further.
How thick should a mattress be?
20 to 25cm suits most people. 30cm and over makes sense if you are over about 100kg, if you sleep on your side and want a deep comfort layer, or if you want the mattress to last ten years or more.
Do I need deep fitted sheets?
Usually, yes. Standard UK fitted sheets cover mattresses up to about 25 to 30cm. For 30cm and over, buy extra-deep sheets (sold for 35 to 40cm) so the corners do not ping off.
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