MattressNextDay Super Firm Foam Double Mattress
The MattressNextDay Super Firm Foam Mattress is built for people who want a genuinely hard sleep surface, which is rarer than you might think.
- Extra-firm feel without sinking in
- Eases pressure at shoulders & hips
- 5-year guarantee
£369
Get the lowest price we've found
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
MattressNextDay Super Firm Foam Mattress
More available sizes
Mattress details
Mattress
MattressNextDay Super Firm Foam Mattress
Size
Firmness
Firm
Construction
Foam
Rolled
Memory Foam
Orthopaedic
Depth (cm)
20
Layers
Layer Details
Deep Reflex Foam
Deep reflex foam gently contours your body without compromising the extra firm feel, which means you get personalised pressure relief across your entire body while the surface stays supportive. Reflex foam is denser and springier than standard memory foam, so you won't feel stuck in one position.
Layer details from mattressnextday.co.uk product page, September 2026.
Key benefits
- A shared size that fits real rooms: At 135 x 190cm, the UK double leaves space for wardrobes and drawers in a typical UK bedroom, where a UK king can feel like a squeeze.
- 67.5cm of width each: Two people sharing get 67.5cm apiece, and the firm reflex foam keeps you lying on the surface rather than rolling towards the middle.
- Room for tables both sides: We suggest a room of at least 2.6m x 2.8m, which usually leaves enough clearance for bedside tables on both sides of the bed.
- Firm support across the full width: The deep reflex foam contours slightly without softening, so a heavier partner sinking in on one side is less noticeable than on a plush mattress.
- Easy to dress: Standard double sheets and a 200 x 200cm duvet fit, both stocked everywhere at every price point, which matters if you're furnishing a whole home at once.
This size suits you if...
You share the bed every night and both prefer a genuinely hard surface, or you sleep alone and want spreading-out room, perhaps with a dog or cat that has claimed a corner. It also makes sense for a guest room that hosts visiting couples: the extra firm feel divides opinion, but the size handles two adults comfortably in a modest spare room.
Consider another size if...
You and your partner keep waking each other, or 67.5cm each feels tight. We'd recommend the UK king instead: 15cm wider and 10cm longer, giving 75cm each, provided your room allows at least 2.7m x 2.9m.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
Is the UK double Super Firm Foam Mattress big enough for a couple?
Yes, for most couples. The UK double measures 135 x 190cm, giving two sharers 67.5cm of width each. The extra firm surface helps here: because you lie on the foam rather than sinking into it, you're less likely to drift towards a partner's dip. Restless sleepers or taller couples may still prefer the UK king.
Will a UK double fit my bedroom with bedside tables on both sides?
Usually, yes. We suggest a room of at least 2.6m x 2.8m for a UK double, and around 3m x 3m is the comfortable norm. That typically leaves room for a table each side plus walking space at the foot, which is precisely why the double remains the standard couples' size in UK homes.
How much bigger is the UK king than the UK double?
The UK double is 15cm narrower and 10cm shorter than the UK king. For two people sharing, the UK king gives 75cm each, so the UK double gives 7.5cm less each. If you're tempted to size up, allow a room of at least 2.7m x 2.9m for the UK king.
Can I get the double Super Firm mattress up a narrow staircase?
It's an all-foam build with no springs, and at 135cm wide it's a more manageable shape than a UK king on turning stairs in older terraces or tight new build landings. MattressNextDay doesn't publish delivery dimensions for this size, so check the brand's own guidance before buying if access is tight.
Where can I compare prices for this mattress in a UK double?
Use the comparison table on this page. The prices shown here are live and updated as retailers change them, so you're always seeing current UK double pricing rather than a figure that was accurate last month. It's a quicker route than checking each retailer yourself.