Arthur Sleep Ortho Arthur Mattress
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Mattress
Arthur Sleep Ortho Arthur Mattress
Size
Firmness
Firm
Construction
Pocket Spring
Depth (cm)
Layers
2
Layer Details
Gel foam comfort layer
A gel foam layer sits at the top and forms the comfort layer. It adds a little cushioning over the firm springs below, and the gel is there to help control temperature.
Pocket spring core
The core is made of pocket springs, each housed in its own fabric pocket. That lets the springs move independently, so you get firm support that responds to your body rather than moving as one sheet.
Layer details from arthursleep.co.uk and mattressman.co.uk product pages, October 2026.
- Fits compact rooms: At 90cm wide, this single leaves space for a desk and wardrobe in a child's room where every foot of floor matters.
- Firm support for growing sleepers: The firm pocket spring feel gives teens and heavier solo sleepers steady support, with springs that respond individually rather than the whole surface sinking.
- A sensible guest bed: Firm mattresses cope well with irregular use, which makes this single a practical choice for a spare room that spends most of its week as an office.
- Two can fit where one double cannot: For siblings sharing, a pair of 90cm singles plus a walkway will often go where a bigger bed simply would not.
- Cheap, easy bedding: Standard single sheets and a 135 x 200cm single duvet fit, and both are the most widely stocked bedding of any UK size.
This size suits you if...
You're buying for a child or teenager and want a firm, supportive base that lasts through the growing years, you sleep alone in a compact room or first flat where 90cm of width is all the space allows, or you're kitting out a guest room and want a mattress that stays supportive between visits.
Consider another size if...
You're an adult who sleeps in this bed every night and finds 90cm restrictive when you turn over. The UK double, 45cm wider and the same length, gives far more room; we suggest at least 2.6m x 2.8m of floor space for it.
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How big is the Ortho Arthur in a UK single?
This size measures 90 x 190cm, which is 3ft x 6ft 3in. That is the standard UK single, so it fits ordinary single frames, divans and most children's beds. We suggest a room of at least 2.1m x 2.8m so you have space to walk around and change the bedding comfortably.
Is the Ortho Arthur UK single suitable for a child's bed?
Yes, with one caveat. The firm pocket spring support suits children and teens well, as it keeps a growing spine level rather than letting hips sink. Lighter children who sleep on their side may find it a little solid at the shoulder, so it works best for back and front sleepers.
Will the Ortho Arthur single fit a bunk or mid sleeper frame?
The 90 x 190cm footprint matches standard UK bunk and mid sleeper frames. The catch is depth: raised frames usually set a maximum mattress height for the safety rail, and Arthur Sleep doesn't publish a depth for this mattress, so check with the retailer against your frame's limit before ordering.
Is a UK single Ortho Arthur good for a guest room?
It's a reasonable fit. A firm pocket spring mattress handles occasional use well, and the 90cm width means a spare room can still double as an office, or even take two singles for visiting family. Guests who are lightweight side sleepers may find the firm feel less forgiving for longer stays.
Should I size up from the single to the double?
If an adult will sleep on it every night, probably. The UK double is 45cm wider than the UK single and the same length, which is a noticeable difference when you turn over. It needs more floor space though: allow at least 2.6m x 2.8m for the UK double against 2.1m x 2.8m for the single.