Wentworth Mercer Mercer 3000 Pocket Pro King Size Mattress
The Wentworth Mercer Mercer 3000 Pocket Pro Mattress combines a pocket spring core with extra layers of mini springs and a double-sided, flippable build, which means firm, bouncy support you can turn to even out wear.
- Firm support for back & front sleepers
- Springs adapt to each sleeper
- Flip it to even out wear
£839
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Wentworth Mercer Mercer 3000 Pocket Pro Mattress
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Mattress details
Mattress
Wentworth Mercer Mercer 3000 Pocket Pro Mattress
Size
Firmness
Firm
Construction
Pocket Spring
Wool
Depth (cm)
32
Layers
5
Layer Details
Wool, cashmere and silk layers
Two layers of a wool, cashmere and silk blend sit at the top. They add a cosy, soft-touch surface over the firm feel beneath.
Polyester fibre layers
Two layers of polyester fibres add to the comfort layer. They give a little extra cushioning between the surface and the springs.
Cotton and polyester layers
A blend of cotton and polyester forms two moisture-wicking layers. They help draw moisture away as you sleep.
Mini pocket springs
Two layers of 1000 mini springs add a bouncy feel. You get a springier, more responsive surface over the core.
Pocket spring core
A core of 1000 pocket springs adapts to the movement and weight of each sleeper. That means support tailored to your body, and the firm feel is rooted here.
Layer details from mattressonline.co.uk product page, November 2026.
Key benefits
- More room each: At 150 x 200cm, the UK king gives 7.5cm more each than the UK double, which means fewer nudged elbows and less waking when one of you turns over.
- Length for a tall partner: The UK king is 10cm longer than the UK double, so a partner over six foot can stretch out without their feet hanging off the end.
- Less disturbance from early starts: The 1000 pocket spring core adapts to each sleeper's weight and movement, so someone getting up hours before you should be felt a little less on your side.
- Firm right across the bed: The firm feel runs the full 150cm width, which suits a couple who both sleep on their backs or fronts and want to stay lifted rather than sink.
- Two sides to sleep on: Yes, flipping a 32cm deep UK king takes two people, but turning it spreads the wear from two sleepers across both faces.
- Room to plan for: We suggest at least 2.7m x 2.9m for the UK king, which leaves space to walk round a 5ft x 6ft 6in mattress.
This size suits you if...
You share the bed every night and have started bumping into each other on a double, one of you is over six foot and keeps running out of length, or you both want firm support and keep each other awake on different schedules.
Consider another size if...
Your bedroom is smaller than our suggested 2.7m x 2.9m. We'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
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FAQ's
Is the Mercer 3000 Pocket Pro UK king big enough for two people?
For most couples, yes. The UK king gives 75cm each, which is 7.5cm more each than the UK double. If you still feel crowded, perhaps with a dog joining you most nights, the UK super king gives 90cm each, although it needs a larger room.
Will a tall person fit on the Mercer 3000 Pocket Pro in a UK king?
The UK king is 200cm long, or 6ft 6in, and 10cm longer than the UK double. That extra length is often the real reason to upgrade when one partner is over six foot. The UK super king is the same length, so sizing up beyond the UK king adds width only.
What size room do I need for a UK king Mercer 3000 Pocket Pro?
We suggest at least 2.7m x 2.9m. Main bedrooms in new builds can feel smaller than the floor plan once fitted wardrobes and bedside tables go in, so measure the space you'll actually have left before committing to a UK king.
Can one person flip the Mercer 3000 Pocket Pro king size?
Probably not comfortably. It's 32cm deep and double-sided, and a UK king of that depth is heavy to turn. Wentworth Mercer doesn't publish a weight for this mattress, so plan on two people for each flip.
Should I get the UK king or UK super king Mercer 3000 Pocket Pro?
The UK king is 30cm narrower than the UK super king and the same length, giving 15cm less each. If your room allows at least 3m x 2.9m and you want the most space, choose the UK super king. Otherwise the UK king is a sensible step up from a double.