Hypnos Cawthorne Support Mattress
Mattress
Hypnos Cawthorne Support Mattress
Size
Firmness
Firm
Construction
Depth (cm)
25
Layers
7
Layer Details
- Cover. A soft to touch Belgian damask cover, which gives a more traditional, upholstered feel than a knitted stretch fabric.
- Comfort layer. A blend of cotton and polyester that combines their comforting properties with increased breathability and moisture wicking. In practice, that means less clamminess on warmer nights.
- eOlus fibres. Hypnos' exclusive eOlus fibres are made from recycled materials and spun into breathable fibres that promote airflow to dispel heat. They also contribute to the secure, firmer feel this mattress is built around.
- Soft White Fibres. Soft synthetic fillings that create a cosy feel while staying durable and resilient. They're designed to maintain their shape rather than compressing into dips over time.
- Support pad. A dual density polyester pad that protects the spring unit and encourages equal weight distribution, which means the springs beneath wear evenly.
- Spring core. 1200 ReActive springs, each sitting in its own fabric pocket to increase responsiveness and isolate movement. You should feel less of a partner shifting about on the other side.
- Edge support. The outer rows of springs use a firmer gauge, reinforced with a durable rod edge. That gives you a sturdier perimeter for sitting on the edge and makes the full sleeping surface usable.
Layer details from mattressonline.co.uk product page, September 2026.
- Real space for one: At 120cm wide, it's 30cm wider than a UK single, so a solo adult can sprawl, starfish or shift position without meeting the edge.
- Fits rooms a double won't: It's 15cm narrower than a UK double, which is often the difference between a door that clears the bed and one that doesn't.
- Firm support at 4ft: The 1200 ReActive pocket springs give a genuinely firm surface, and in this width a solo back or front sleeper gets that support across the whole bed.
- Usable right to the edge: Firmer gauge outer springs and a rod edge mean the full 120cm is sleepable, which matters more here than on a wider size.
- Easy to buy for: 4ft is a standard UK size, so small double frames and fitted sheets are simple to find, paired with a standard double duvet.
This size suits you if...
You sleep alone and have outgrown a UK single but can't spare the width a full double takes, your bedroom is a box room, loft conversion or studio where every centimetre of floor counts, or you're furnishing a guest room or holiday let where couples stay occasionally rather than every night.
Consider another size if...
You share the bed with a partner most nights, because 120cm is tight for two adults long term. We'd recommend the UK double instead, which is 15cm wider; allow at least 2.6m x 2.8m of room for it.
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Is the Hypnos Cawthorne small double big enough for a couple?
For occasional nights, yes. At 120 x 190cm two adults can share, and the pocket springs keep one person's movement from travelling across the bed. For every night, though, it's a squeeze, and the firm feel gives you less give when you're pressed together. Couples sharing nightly would be happier on the UK double, which is 15cm wider.
What room size do I need for the Hypnos Cawthorne small double?
We suggest a room of at least 2.4m x 2.8m. That leaves enough space to walk round the bed and open drawers or a wardrobe without shuffling sideways. It's why the UK small double works in box rooms and loft conversions where a UK double, which needs at least 2.6m x 2.8m by our guidance, starts to dominate.
Should I buy the Hypnos Cawthorne in a small double or a double?
It usually comes down to the room rather than the mattress, since the firm feel and 1200 pocket springs are the same in both. The UK small double is 15cm narrower than the UK double and the two are the same length. Sleeping solo in a compact room, take the small double; sharing regularly, the extra width of the UK double is worth having.
Will the Hypnos Cawthorne small double fit a standard double bed frame?
No, and it's a common mix-up. A UK small double is 120 x 190cm, while a standard UK double frame is built for 135 x 190cm, so this mattress would leave a 15cm gap. You need a 4ft small double frame, which is a standard UK size and easy to find. Duvets are simpler: a standard double duvet works fine.
Is the small double a good guest room size?
It's arguably the most practical guest room size. Solo visitors get far more space than a UK single offers, occasional couples can manage for a few nights, and the 4ft width leaves room in a small second bedroom for a chair or chest of drawers. The Cawthorne's firm feel also tends to divide people less over short stays than a very soft mattress would.