An extra firm mattress will score around a 9 out of 10 on the firmness scale and is a step up in sturdiness from a firm mattress (usually 8 out of 10), offering ultimate support and rigidity.

The extra firm side merely knocks out the comfort layer. Alongside a wider review panel, Sr Sleep Writer Ruth Jones awarded the Plank Firm an impressive 4.5 out of 5 following a three week testing ...

Best for back and stomach sleepers: Tuft & Needle Original Mattress List price: from $745 Mattress type: memory foam Firmness: firm Height: 9.5 in Warranty: 10-year limited-term warranty ...

Best memory foam mattress 2025 at a glance Best for a high level of firm support: Emma Original Mattress - £499, Emma Best for a combination of firm support and sublime comfort: Eve The Premium ...

Best medium-firm memory foam mattress: Leesa Original Hybrid Mattress Leesa Original Hybrid Mattress Leesa Sleep US $1,499.00 $1,199.00 ...

The extra firm side of the Plank Firm Luxe is the firmest bed on our best king-size mattress list, at a whopping 9.5 out of 10. The soft side of the flippable Layla Hybrid bed is the softest, at 3.1.