Firmness
Medium Firm
Type
Foam
Depth (cm)
26
Number of Layers
4
Trial Period (nights)
Warranty (years)
5
Price Range
£599 to £999
Best Sleeping Position(s)
Certifications
Assessed from Sealy's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
The Duchess suits sleepers who want a traditional, supportive feel rather than the deep sink of memory foam. Layers of Sealy medium foam over the PostureTech springs give a balance of cushioning and pushback, which means most back and combination sleepers should feel held rather than swallowed. The EdgeGuard border adds durability and edge-to-edge support, useful if you share a bed and use the full width. It comes with a 5 year guarantee, and a BugShield treatment on the fabric. The price range of £599 to £999 across sizes sits in sensible mid-market territory for a sprung Sealy, though you'll need to be happy turning it regularly to keep it wearing well.
Key Features & what's inside
- Quilted Surface. A quilted sleep surface sits on top, which means a soft, slightly cushioned first impression when you lie down. It's a traditional finish rather than a plush pillow-top feel.
- Sealy Medium Foam. Generous layers of Sealy medium foam add comfort between you and the springs. This is what softens the medium firm support so it doesn't feel hard at the surface.
- PostureTech Core Support Springs. The PostureTech Core Support system uses springs that gradually get firmer as pressure increases, which means heavier areas like your hips get deeper support while lighter areas rest more gently. The result is pressure relief without sagging.
- EdgeGuard. EdgeGuard reinforces the perimeter for added durability and edge-to-edge support. In practice, that gives you more usable sleeping space right up to the sides.
Layer details from sealy.co.uk product page, September 2026.
Who's it NOT for?
If you want a no-turn mattress, look elsewhere: this is double-sided and needs turning regularly. It's also not for fans of that slow-sinking memory foam hug, as the medium foam and springs give a more traditional, responsive feel. Lightweight side sleepers may find medium firm slightly too firm.
Sealy Duchess Contract Mattress
How firm is the Sealy Duchess Contract mattress?
It's listed as medium firm, a supportive feel that suits most back and front sleepers. The Sealy medium foam layers soften the surface, but lightweight side sleepers who need more give at the shoulder may find it a little too firm.
Do you need to turn the Sealy Duchess Contract mattress?
Yes. Sealy's page indicates this is a double-sided mattress that should be turned regularly. It's a small chore, but turning helps the comfort layers wear evenly on both sides over time.
How deep is the Sealy Duchess Contract mattress?
Sealy's product description states the depth is 26cm, although the technical specifications on the same page list 32cm for all sizes. If exact depth matters for your fitted sheets or bed frame, it's sensible to confirm with the retailer before ordering.
What guarantee comes with the Sealy Duchess Contract?
Sealy's own site states a 5-year guarantee, and the retailer listing shows the same 5-year cover. As always, check the terms at your chosen retailer before you buy.
What sizes does the Sealy Duchess Contract come in?
It's available in UK Single, Double, King and Super King. Prices run from £599 to £999 depending on the size you choose.
Couldn't find an answer to your question? Send us a message