The Dormeo Octasmart Mattress Topper is a 7cm medium-firm topper with Aerocell foam over zoned Octaspring foam springs.
The Dormeo Octasmart Mattress Topper is a 7cm medium-firm topper that puts supportive Aerocell foam over a layer of Octaspring foam springs in three body zones. Unlike most toppers it is designed to firm a bed up rather than soften it, and it costs £379 for a UK double at the time of writing (September 2026). Dormeo’s reviews average 4.1 out of 5 from 440 buyers.
The Octasmart topper page on dormeo.co.uk rates it medium/firm, the firmest of Dormeo’s three 7cm Octasmart toppers. The difference is the top layer.
| 7cm Octasmart topper | Top layer | Firmness (Dormeo) | Double, regular price |
|---|---|---|---|
| Octasmart | Aerocell foam | Medium/firm | £379 |
| Octasmart Plus | Memory foam | Medium | £249 |
| Octasmart Deluxe | Memory foam, top and base | Medium/soft | £539 |
We score the Octasmart topper 6 out of 10 for firmness. Bed Advice UK, the consumer site of the National Bed Federation, notes in its topper buying advice that a firmer topper can give extra support to a too-soft bed, while a soft one adds cushioning and pressure relief. That makes this the topper for back and front sleepers on a mattress that has softened slightly. The same guide is clear that no topper can fix deep dips, because it will mould to them.
Firm is not automatically better for backs. A Lancet trial of 313 adults with chronic low-back pain (Kovacs et al., 2003) found medium-firm mattresses gave better results than firm ones after 90 days, so the aim is a level, medium-firm surface rather than a hard one. Dormeo says the topper is 100% recyclable; the claim that it has a 50% lower environmental footprint comes from Dormeo’s internal assessment.
Before buying any topper, look at the age of the mattress underneath. Bed Advice UK recommends replacing a mattress every seven years and notes that after more than 20,000 hours of use it has built up sweat, skin cells and general wear; on a mattress that old, the money for this topper may be better put towards a new one.
| UK size | Dimensions | Regular price at Dormeo |
|---|---|---|
| Single | 90 x 190cm | £319 |
| Double | 135 x 190cm | £379 |
| King | 150 x 200cm | £439 |
| Super king | 180 x 200cm | £499 |
Dormeo’s 200-night trial covers toppers as well as mattresses. The Octasmart topper warranty covers the core for eight years and the removable cover for one, but only the first two years are full cover; from year three you pay a rising share of a replacement, 45% in the fourth year. There is no small double.
| Brand | Dormeo |
|---|---|
| Material | Supportive Aerocell foam over a layer of Octaspring foam springs in three body zones, on a foam base. Smart performance cover with comfort pockets, forming Dormeo's Octavent air system with the springs. |
| Firmness | Medium firm (6/10) |
| Height | 7 cm |
| Weight limit | 140 kg |
| Sleep trial | 200 nights |
| Warranty | 8 years |
| Delivery | Free delivery in 7-10 days |
| Available sizes | 90x190, 135x190, 150x200, 180x200 |
| Overall score | 7.6/10 |
“The Octasmart topper is for back sleepers whose mattress has become a little too soft but is not sagging, because its medium-firm Aerocell surface adds support rather than cushioning. It costs more than the memory foam Plus topper in every size, so choose it only if you want that firmer feel.”
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