Silentnight UltraGel 1400 Pocket Mattress
Mattress
Silentnight UltraGel 1400 Pocket Mattress
Size
Firmness
Firm
Construction
Depth (cm)
29
Layers
2
Layer Details
- UltraGel™ layer. A gel infused comfort layer that Silentnight describes as smart and responsive, designed to adapt to your movements. In practice that means comforting, soothing cushioning at the surface rather than a deep sink.
- Mirapocket® springs. 1400 individual pocket springs that adjust to your body weight, giving ease of movement and zoned support. Silentnight states this zoning is scientifically proven to improve spinal alignment and posture.
Layer details from silentnight.co.uk product page, September 2026.
- Real room to spread out alone: At 120cm wide, this size is 30cm wider than the UK single, which means a solo back or front sleeper can stretch out on the firm surface.
- Fits rooms a double would crowd: Being 15cm narrower than the UK double, it can be the difference between a bedroom that works and a door that no longer clears the frame.
- Firm support across the full width: The 1400 Mirapocket springs adjust to your body weight individually, so support stays consistent whether you sleep centred or drift to one edge.
- Gel cushioning without the sink: The UltraGel comfort layer adds a touch of surface softness, which means the firm feel is cushioned rather than board-like in a smaller bed.
- A standard UK size: The 4ft small double is a standard UK size, so finding a frame and fitted sheets is straightforward.
This size suits you if...
You sleep alone most nights and want more width than a single without giving up floor space, perhaps in a box room, studio or loft conversion where every centimetre beside the bed matters. It also works for a guest room that hosts the occasional couple, since two people can share a firm 120cm mattress for a weekend even if they wouldn't want to every night. Allow at least 2.4m x 2.8m of room.
Consider another size if...
You share the bed every night, as 120cm is a squeeze for two on a firm mattress long term. We'd recommend the UK double instead: it's 15cm wider, the same length, and needs a room of at least 2.6m x 2.8m.
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.
Is the Silentnight UltraGel 1400 small double big enough for a couple?
For occasional nights, yes. Two adults can share the 120cm width for a weekend stay, which makes this size a sensible guest room choice. For every night, most couples find a small double tight, especially on a firm mattress where you don't sink into your own dip. Sharers should consider the UK double, which is 15cm wider.
What room size do I need for the UltraGel 1400 in a small double?
We suggest allowing at least 2.4m x 2.8m. That gives you space to open the door, get in and out on at least one side, and add a small chest of drawers. This is our own guidance rather than Silentnight's, so treat it as a comfortable minimum, not a hard rule.
Is the small double UltraGel 1400 a good upgrade from a single?
It's a strong step up for a solo sleeper. You gain 30cm of width over the UK single while the length stays the same at 190cm, so a teenager or adult moving up won't need a longer room, just a slightly wider spot for the bed. The firm feel suits back and front sleepers best.
Will the small double fit in a loft conversion or box room?
Often, yes, and that's the main reason to pick it. At 120cm wide it leaves walking space where a 135cm double would leave none, which matters under sloping ceilings or beside a door that swings inwards. Measure your usable floor first and check it against our suggested minimum of 2.4m x 2.8m.
Should I buy the UltraGel 1400 in a small double or a double?
Choose the small double if you sleep alone, or the bed is for guests, or your room is under 2.6m wide. Choose the UK double if two of you will share it nightly: it's 15cm wider, the same 190cm length, and we suggest at least 2.6m x 2.8m of room for it. Compare prices for both using the retailers listed on this page.