Firm vs Medium vs Soft Mattress

Mattress firmness describes how much a mattress resists sinking under body weight. A firm mattress keeps the body closer to the surface with minimal sink, a medium mattress balances support with some contouring, and a soft mattress allows deeper sinking and closer body-hugging, typically with a plusher top layer.

This comparison spans five mattresses across the three tiers: firm — the Sealy Posturepedic Elevate Blackwood (£857) and Sealy Steeple Ortho Plus (£447); medium — the DOSLEEPS 9-Zone Double (£115.01, 27cm) and Vesgantti 4ft6 Hybrid Double (£148.40, 26cm); and soft — the Wilson Beds 3ft Single (£49.49).

The Sealy Posturepedic Elevate Blackwood (£857) is marketed as a firm, orthopaedic mattress under Sealy's established Posturepedic range, positioned at the premium end of this comparison. The Sealy Steeple Ortho Plus (£447) is also firm, described as 'ortho plus' for orthopaedic-style support, at roughly half the Blackwood's price.

Both firm options come from Sealy and share an orthopaedic positioning, aimed at sleepers who want minimal sink and a supportive, level sleeping surface — often recommended for back pain or for those who sleep on their back or front.

The DOSLEEPS 9-Zone Double (£115.01, 27cm) combines memory foam with a pocket-sprung base and a 9-zone design intended to vary support across the body, marketed as medium-firm with edge support and motion isolation. The Vesgantti 4ft6 Hybrid Double (£148.40, 26cm) combines breathable foam with individually pocketed springs, also marketed as medium-firm, as part of its Classic Box Top collection.

Both medium options are hybrids at a similar depth (26–27cm) and price range (£115–£148), aiming for a balance between the contouring of foam and the responsiveness of springs, positioned as medium-firm rather than a softer medium feel.

The Wilson Beds 3ft Single (£49.49) is the only soft-feel mattress in this comparison, combining a memory foam top layer with a spring core in a single size, at roughly 6.5in deep. It is also the cheapest mattress across all three firmness tiers here.

A soft feel typically means more sink and closer body-hugging than the medium or firm options above, which can suit lighter sleepers or side sleepers wanting more cushioning at the shoulders and hips, though the Wilson Beds mattress is a single size and priced accordingly.

Back and stomach sleepers generally benefit from firmer support that keeps the spine level, making the Sealy Posturepedic Elevate Blackwood or Sealy Steeple Ortho Plus more suitable choices in this comparison. Side sleepers usually need more give at the shoulder and hip, which points towards the medium-firm DOSLEEPS or Vesgantti hybrids, or the softer Wilson Beds mattress for lighter side sleepers.

• Heavier sleepers: firm mattresses (Sealy Posturepedic Elevate Blackwood, Sealy Steeple Ortho Plus) resist excess sinking and maintain support
• Average-weight, mixed-position sleepers: medium-firm hybrids (DOSLEEPS 9-Zone, Vesgantti Hybrid) balance contouring and support
• Lighter or side sleepers wanting more cushioning: the soft-feel Wilson Beds mattress allows more sink at the shoulders and hips

Choose firm — the Sealy Posturepedic Elevate Blackwood or Sealy Steeple Ortho Plus — if you're a back or stomach sleeper, a heavier sleeper, or specifically want orthopaedic-style support. Choose medium — the DOSLEEPS 9-Zone or Vesgantti Hybrid — for a balance of contouring and support that suits mixed sleep positions. Choose soft — the Wilson Beds 3ft Single — if you're a lighter or side sleeper wanting deeper cushioning at the shoulders and hips, and only need a single-size mattress.

• Q: Is a firmer mattress always better for back pain? A: Not universally — firm mattresses suit back and stomach sleepers by keeping the spine level, but side sleepers with back pain may need more give at the hips and shoulders, which points towards medium or soft.
• Q: Does a higher price mean a firmer or better mattress? A: No — this comparison's most expensive mattress (Blackwood, £857, firm) and cheapest (Wilson Beds, £49.49, soft) sit at opposite firmness extremes, so price reflects brand and construction more than firmness level.
• Q: Can one mattress suit two sleepers with different firmness preferences? A: A medium-firm hybrid, such as the DOSLEEPS 9-Zone or Vesgantti Hybrid, is usually the best compromise for couples with differing preferences, since it avoids the extremes of firm or soft.
• Q: Are the two Sealy mattresses interchangeable? A: No — the Posturepedic Elevate Blackwood is a premium range at £857, while the Steeple Ortho Plus is £447; both are firm and orthopaedic-positioned but at different price and product tiers.

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