Ergoflex 5G Mattress
The Ergoflex 5G is an all-foam memory foam mattress with a 23cm profile, built around a 9cm layer of HD visco-elastic memory foam, which means it moulds closely to your shape and eases pressure on hips and shoulders.
- Deep, cradling feel for side sleepers
- Airflow layer moves heat away
- 30-night trial & 10-year guarantee
£369

Get the lowest price we've found
The Ergoflex 5G holds a Which? Best Buy award for 2024 to 2026, which offers some independent reassurance. Ergoflex doesn't publish a firmness rating, so if you have a strong preference either way it's worth using the 30-night trial to judge it for yourself. Delivery is free and next-day, and the mattress carries a 10-year guarantee.
Mattress specifications
Firmness
Type
Memory Foam
Depth (cm)
23
Number of Layers
5
Trial Period (nights)
30
Warranty (years)
10
Price Range
£369 to £747
Certifications
Assessed from Ergoflex's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
The main draw here is the depth of the memory foam layer: 9cm of HD visco-elastic foam gives a deep, cradling feel that suits side sleepers and anyone with pressure point pain. Memory foam has a reputation for sleeping warm, but Ergoflex has placed a 5cm Cool-Sleep airflow layer directly beneath it, plus a TENCEL cover, both aimed at moving heat away from your body. The brand also states the mattress is naturally anti-allergenic, useful if dust mites trouble you. Yes, the 30-night trial is on the shorter side, but a slow-response foam like this tends to reveal its character quickly, and the 10-year guarantee covers the long run.
Key features & layer details
Cover
Tencel outer cover - natural and breathable
Top Layer
Micro-fine inner protective cover
Layer 2
True high-density visco-elastic memory foam
Layer 3
Cool-Sleep™ airflow system
Layer 4
High resilience foam base
Best suited for?
Side sleepers
The 9cm layer of HD visco-elastic foam gives a deep, cradling feel, which means shoulders and hips can sink in comfortably.
Allergy sufferers
The brand states the mattress is naturally anti-allergenic, which is useful if dust mites trouble you and you want a calmer sleeping surface.
Back sleepers
Slow-response memory foam over a high resilience foam base gives a hugging, contoured feel that suits those who like to sink in.
If you dislike the slow, hugging feel of memory foam and prefer a springy, on-top-of-the-bed sensation, this isn't the mattress for you. Hot sleepers who have struggled with foam before should also weigh it carefully, as the airflow layer helps but can't change the nature of the material.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Ergoflex 5G Mattress
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FAQ's
How deep is the Ergoflex 5G mattress?
It's 23cm deep in total, made up of five layers: a 9cm memory foam comfort layer, a 5cm airflow layer and a 9cm high-resilience foundation, wrapped in a micro-fine inner cover and a TENCEL outer cover.
Does the Ergoflex 5G come with a trial period?
Yes, Ergoflex offers a 30-night trial, so you can sleep on it at home before committing. That's shorter than many brands offer, although memory foam tends to feel familiar within a few weeks. The mattress is also covered by a 10-year guarantee.
Is the Ergoflex 5G good for allergy sufferers?
Ergoflex states the mattress is naturally anti-allergenic, and the all-foam construction avoids the hollow spaces where dust mites often gather in sprung mattresses. If allergies are a big factor for you, this is a reasonable choice.
What sizes does the Ergoflex 5G come in?
It's available in UK Single, UK Double, UK King and UK Super King, plus EU Double and EU King, which is handy if you have a European bed frame.
Does the Ergoflex 5G sleep hot?
Memory foam does hold more warmth than springs, but the 5G is built with this in mind. A 5cm Cool-Sleep airflow layer sits directly under the memory foam to circulate air, and the TENCEL cover is a breathable, moisture-managing fibre.
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