Silentnight UltraGel 3000 Mirapocket Box Top Firmer King Size Mattress
The Silentnight UltraGel 3000 Mirapocket Box Top Firmer is a firm hybrid with a softer story on top.
- Firm feel with a cushioned top
- Extra support under your hips
- Minimises partner disturbance
£1,135
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.
Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress
More available sizes
Mattress details
Mattress
Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress
Size
Firmness
Firm
Construction
Foam
Pocket Spring
Hybrid
Gel
Depth (cm)
35
Layers
4
Layer Details
Pillow top
An additional comfort layer sewn on top, which means a more luxurious, cushioned feel the moment you lie down. It softens the first impression of what is otherwise a firm mattress.
UltraGel
A gel infused foam layer that adapts to your shape and movements, distributing your weight evenly. According to the listing it's five times more breathable than memory foam, so it should hold less heat.
Mini Pocket Springs
A layer of 1,000 mini pocket springs that work like bellows, pushing air through the comfort layers as you move. They also help decrease motion transfer, so you feel less of a restless partner.
Mirapocket Springs
The main support unit of 2,000 Mirapocket springs, zoned so the centre third is firmer. That means greater support under your midsection and encouragement towards better spinal alignment.
Layer details from mattressonline.co.uk product page, September 2026.
Key benefits
- More room each: The UK king gives 75cm each for two sharing, 7.5cm more each than a UK double, so elbows and knees stop meeting in the middle of the night.
- Length for taller sleepers: At 200cm long, the UK king is 10cm longer than a UK double, which means a partner over six foot can stretch out without feet hanging off the end.
- Less disturbance from early risers: The mini pocket spring layer helps reduce motion transfer, which means the partner who leaves hours earlier is less likely to wake the one still asleep.
- Firm support across both halves: The Mirapocket springs are zoned firmer through the centre third, so each of you gets extra support under the hips on your own side of the bed.
- Space to shift position: The extra width suits anyone propping pillows or changing position often, such as during pregnancy, without taking over a partner's side.
- A step short of a super king: You get noticeably more space than a UK double without needing a room large enough for the UK super king.
This size suits you if...
You share the bed every night and keep bumping into each other on a UK double, one of you is tall enough that 190cm feels short, or you sleep on different schedules and want a little more distance from a partner who gets up early.
Consider another size if...
Your bedroom falls short of our suggested 2.7m x 2.9m once wardrobes are in. The UK double would suit you better, and we suggest at least 2.6m x 2.8m for the UK double.
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
What size room do I need for a Silentnight UltraGel 3000 UK king?
We suggest allowing at least 2.7m x 2.9m for a UK king. New build master bedrooms can feel smaller than their floor plan once fitted wardrobes and bedside tables go in, so measure the space that is actually free before ordering a mattress this size.
How much space does each person get on the UltraGel 3000 UK king?
The UK king gives 75cm each for two people sharing. That is 7.5cm more each than the UK double, which gives 67.5cm each, and 15cm less each than the UK super king at 90cm each.
Is the Silentnight UltraGel 3000 UK king long enough for someone over 6ft?
The UK king is 200cm long, 10cm longer than the UK double, the UK small double and the UK single. If one of you is over six foot, that extra length is often the real reason to upgrade, and the UK super king adds width but no further length.
Should I get the UltraGel 3000 in a UK king or UK super king?
The UK super king is 30cm wider than the UK king and gives 90cm each, but we suggest at least 3m x 2.9m for it. If your room is tighter than that, the UK king gives a good step up from a double while the UK super king needs noticeably more floor space.
Is the UltraGel 3000 UK king heavy to move?
Across verified owner reviews, weight and depth come up as practical considerations, and a 35cm deep mattress at 150 x 200cm is a lot to handle alone. Silentnight doesn't publish a weight for this size, so plan on two people for rotating it.