Arthur Sleep Spare Arthur Mattress
Mattress
Arthur Sleep Spare Arthur Mattress
Size
Firmness
Medium Firm
Construction
Depth (cm)
Layers
Layer Details
- Real space for one: At 30cm wider than the UK single, it gives a solo sleeper genuine room to spread out without a bigger frame footprint.
- Fits compact rooms: Being 15cm narrower than the UK double, it slots into box rooms and loft bedrooms where every centimetre beside the bed matters.
- Springs that respond individually: The pocket springs move independently under your body, which means support follows your spine rather than the whole surface tilting when you shift.
- Middle-ground firmness: The medium firm tension suits back, side and front sleepers alike, useful in a guest room where you can't predict who's staying.
- Easy bedding to find: 4ft is a standard UK size, so small double fitted sheets and frames are widely stocked, and a standard double duvet drapes generously.
This size suits you if...
You sleep alone and have started to feel hemmed in by a single, your bedroom is too tight for a 135cm double, or you're kitting out a guest room where couples stay occasionally rather than nightly. Allow at least 2.4m x 2.8m of floor space and the UK small double leaves you room to actually walk around the bed.
Consider another size if...
You share the bed every night, because 120cm is workable for the odd stay but a squeeze long term. We'd recommend the UK double instead, which is 15cm wider; allow at least 2.6m x 2.8m for that size.
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 Spare Arthur small double big enough for a couple?
For occasional nights, yes. At 120cm wide, two adults can share comfortably enough for a weekend stay, which is why this size works well in guest rooms. For a couple sleeping together every night, it's a little tight, and the UK double at 135cm wide is the sensible minimum.
What room size do I need for the Spare Arthur in a UK small double?
We suggest allowing at least 2.4m x 2.8m. That gives you space to open the door, walk down one side of the bed and fit a chest of drawers. It's our own guidance rather than the manufacturer's, so treat it as a comfortable starting point, not a hard rule.
Is the small double Spare Arthur a good upgrade from a single?
Yes, and it's the most common reason people buy this size. The UK small double is 30cm wider than the UK single but exactly the same length, so it often fits the same wall while giving a teenager or solo adult noticeably more room to move at night.
Should I get the Spare Arthur in a small double or a double?
It usually comes down to the room. The UK small double is 15cm narrower than the UK double, and both are the same length, so measure whether you can allow at least 2.6m x 2.8m. If you can, and you share the bed regularly, the UK double is the better long-term buy.
Does the firmness feel different in the small double size?
No. The medium firm tension and pocket spring construction are the same across every size of the Spare Arthur, so the small double feels the same underneath you as its siblings. What changes is width: to check availability in this size, compare the retailers listed on this page.