The best mattress for a sofa bed: depth and size first, then everything else
The mattress that came with the sofa bed is usually the reason guests leave early. Replacing it is possible, but "sofa bed" covers several different mechanisms, and the right mattress for one will not go in another. Start with which one you have.
The four kinds
| Kind | How it works | Mattress it takes | Depth |
|---|---|---|---|
| Metal-action pull-out | A folding steel frame with a sprung mesh unfolds from inside the sofa; the mattress folds in three with it | A purpose-made thin sofa-bed mattress | 8 to 12 cm |
| Click-clack / futon | The back folds down flat; the seat and back cushions are the sleeping surface | The cushions; sometimes a thin futon mattress on top | 8 to 15 cm |
| Day bed / guest bed / trundle | A fixed bed frame that looks like a sofa, or a second bed that slides out from under it | A standard mattress | Up to 25 cm |
| Ottoman guest bed / storage sofa bed | A frame that opens to a flat slatted base | A standard mattress | Up to 25 cm |
Only the last two take a normal mattress. The first two take something built for folding.
Metal-action pull-outs
The mattress has to fold into thirds and live inside a sofa, so it is thin and it folds along the same lines for years. Replacement sofa-bed mattresses are sold in 8, 10 and 12 cm depths in foam, memory foam or a thin pocket-sprung version, in sizes to match the frame (usually 4ft or 4ft 6 wide, and often shorter than 190 cm). Buy the deepest your mechanism will close over; 12 cm is a real improvement on 8. Memory foam or a pocket-sprung version over foam for feel; check that it is stated as suitable for a sofa bed, because ordinary foam cracks at the folds.
A standard 20-plus cm mattress will not go in one of these, and if you force it the mechanism will not close. The honest limit of a metal-action pull-out is that it will never be a great bed; it is a great sofa that becomes an adequate bed.
Click-clack and futon
The sleeping surface is the sofa cushions. You can improve it with a thin futon mattress or a 5 cm topper laid on top for guests and stored otherwise. Do not expect much.
Day beds, guest beds, trundles and ottoman guest beds
These are beds, and they take a mattress: measure the frame (many are 3ft single, 4ft small double or a 190 cm length that is shorter than a king), check the depth limit in the instructions, usually around 25 cm so a trundle slides under or an ottoman closes, and buy a proper mattress. A 20 to 22 cm pocket-sprung mattress with a memory foam top and a firm edge is the right thing here: a real spring unit, deep enough to be comfortable, shallow enough for the frame. This is a guest bed that guests will not complain about.
Size
Sofa beds and guest beds lie about size more than any other furniture. "Double" often means 4ft (120 cm) not 4ft 6 (135 cm); lengths are often 180 or 190 cm. Measure the frame's inside dimensions, not the old mattress, which may have been squashed.
When to replace the whole thing
If the sofa bed is a metal-action pull-out that gets used more than a few nights a year, a day bed or guest bed with a proper mattress will cost about the same as a good replacement sofa-bed mattress and sleep far better. The sofa bed's advantage is only that it is also a sofa.
How we fit in
The Empty Nester is 22 cm, medium-firm, pocket-sprung with a memory foam top and a firm edge, in single, small double, double and king. It fits day beds, guest beds, trundles and ottoman guest beds. It does not fit a metal-action pull-out, and we say so on the page.
The short version
- Find out which of the four kinds you have.
- Metal-action pull-outs and click-clacks take thin, purpose-made mattresses; nothing else fits.
- Day beds, guest beds, trundles and ottomans take a standard mattress up to about 25 cm: buy a 20 to 22 cm pocket sprung.
- Measure the frame; "double" is often 4ft.
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