Dunelm Memory Foam Mattress Topper reviewed

The Dunelm Memory Foam Mattress Topper is a 5.7cm layer of visco-elastic foam in a 100% polyester cover, sold in four UK sizes with a two-year guarantee. It averages 4.5 stars from 834 reviews on Dunelm’s product page at the time of writing (September 2026), which makes it one of the most reviewed toppers the retailer sells.

Specification

Prices by size

Prices are Dunelm’s regular prices, checked on 28 September 2026. Dunelm lists the super king at 183cm wide, 3cm more than the 180cm UK standard, so it should reach the edge of the mattress; the other three sizes match standard UK dimensions. Unlike the Dunelm Rebound fibre topper, this one is not sold in a small double. The shop’s other plain memory foam option, the Fogarty Memory Foam Mattress Topper, is 4cm deep and costs £90 in a double; the Dunelm topper is 1.7cm deeper and is the only one of the two with a stated guarantee.

What memory foam does

Visco-elastic foam softens under body heat and pressure and recovers slowly, which is why it spreads the load at the shoulder and hip. The material began as a NASA project. Charles Kubokawa, then a human factors engineer at NASA’s Ames Research Center, described the original “temper foam” to NASA Spinoff: “Once you sat on the foam, it conformed evenly with the contacted body surface and made you settle snugly into the seat.”

That slow contouring is the reason to buy this topper. The Sleep Charity notes that a mattress that is too firm “can apply pressure to our hips and shoulders”, and 5.7cm of memory foam is an inexpensive way to add give where a side sleeper needs it. We rate the Dunelm Memory Foam topper medium-soft, 4 out of 10.

Limits

Care is the weak point. The specification lists the topper as sponge clean only, although the marketing paragraph on the same page mentions a machine-washable cover; we follow the care field. There is no gel or ventilation to offset the warmth of solid memory foam either, so warm sleepers are better served by the Dunelm Gel Fusion, which costs £140 in a double against £120 for this topper. Like every topper, it will do little for a mattress that is already sagging. Dunelm offers no sleep trial and takes change-of-mind returns only on unused items within 28 days.