Wentworth Mercer Deluxe Wool 4000 Pocket Small Double Mattress
The Wentworth Mercer Deluxe Wool 4000 Pocket Mattress is a firm pocket spring mattress with wool and soft synthetic fillings beneath a viscose cover.
- Suits back & front sleepers
- Wool helps regulate temperature
- Minimises partner disturbance
£849
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Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
More available sizes
Mattress details
Mattress
Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
Size
Firmness
Medium Firm
Construction
Pocket Spring
Wool
Depth (cm)
29
Layers
4
Layer Details
Cover
A viscose cover, a soft breathable fabric, finished to a high standard. It gives the sleeping surface a smooth, cosy feel.
Wool
A plush layer of wool fibres for a luxuriously cosy feel. Wool also naturally helps with temperature regulation, so it tends to suit warmer sleepers.
Soft White Fibres
Soft synthetic polyester fillings layered on top of the springs for extra comfort. These add a gentle cushioning between you and the firm support below.
Pocket Springs
The core is 4,000 pocket springs, made from twice tempered steel, that adapt to your shape and movements. Each spring moves independently, which means personalised support and less motion transfer across the bed.
Layer details from mattressonline.co.uk product page, September 2026.
Key benefits
- Space to sprawl on your own: At 30cm wider than the UK single, the UK small double lets you sleep diagonally or stretch out without an arm dropping off the edge.
- Leaves floor where you need it: Being 15cm narrower than the UK double, the UK small double can leave enough clearance for a wardrobe door to open or a bedside table to fit.
- Less disturbance when a guest couple shares: The 4,000 pocket springs move separately, which means two people on a guest night should feel a little less of each other's turning.
- Cooler when sleeping closer together: Wool above the springs helps regulate temperature, which helps on the UK small double, where two bodies sit nearer each other than on a wider bed.
- Straightforward to furnish: The UK small double is a standard 4ft UK size, so finding a frame and fitted sheets to match should take little searching.
This size suits you if...
You sleep alone and want more room than a UK single gives, your bedroom or loft conversion is too tight for a UK double, or you are kitting out a guest room where couples stay for a night or two but nobody shares nightly.
Consider another size if...
You share the bed every night with a partner. We'd recommend the UK double instead, which gives 67.5cm each for two sharing; we suggest at least 2.6m x 2.8m for the UK double.
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FAQ's
Will a Wentworth Mercer Deluxe Wool 4000 UK small double fit in a box room?
We suggest a room of at least 2.4m x 2.8m for a UK small double. At 120 x 190cm, the mattress is 15cm narrower than the UK double, and that margin can decide whether a door still clears the bed. Measure the door swing and any sloping ceiling before you order.
Is the Deluxe Wool 4000 UK small double a good upgrade for a teenager?
For a teenager who has outgrown a UK single, the UK small double adds 30cm of width at the same length, so there is room to move without losing much more floor. The feel is firm, which suits back and front sleepers better than lighter side sleepers, so bear in mind how your teenager sleeps.
Is the Wentworth Mercer Deluxe Wool 4000 small double good for a guest room?
Yes, for occasional couples. The independent springs mean one guest turning over should disturb the other less, and the wool helps keep things cooler at close quarters. For a room where two people sleep every night, the UK double would suit better.
Will a 4ft bed frame fit the Deluxe Wool 4000 small double?
It should. The UK small double measures 4ft x 6ft 3in (120 x 190cm), the standard 4ft UK size. Check that your frame's listed internal dimensions match 120 x 190cm before buying, particularly with older or second-hand frames.
Where can I buy the Wentworth Mercer Deluxe Wool 4000 in a UK small double?
Compare the retailers listed on this page. The prices shown here are updated as retailers change them, so check the table on the day you are ready to order.