Mattress Firmness Guide UK: How to Choose the Right Feel

Understanding Mattress Firmness

Firmness is one of the most important factors in choosing a mattress — and one of the most confusing. What feels firm to one person feels medium to another. Marketing terms like "orthopaedic" or "luxury plush" add to the confusion.

This guide cuts through the jargon to help you understand what firmness level you actually need.

The Firmness Scale Explained

The industry generally uses a 1-10 scale:

  • 1-2 (Extra Soft): Very rare; excessive sinking
  • 3-4 (Soft): Significant contouring; deep sink-in feel
  • 5 (Medium-Soft): Noticeable cushioning with some support
  • 6 (Medium): Balanced feel; most popular
  • 7 (Medium-Firm): Supportive with moderate cushioning; very popular
  • 8 (Firm): Minimal sinking; strong support
  • 9-10 (Extra Firm): Very hard; minimal give

Most UK mattresses fall between 5-8 on this scale. The extremes (1-3 and 9-10) are specialist products.

Firmness vs Support: The Key Distinction

Many people confuse firmness with support. They're different:

  • Firmness: How the mattress feels when you lie on it — the initial sensation
  • Support: How well the mattress maintains spinal alignment — the underlying structure

A soft mattress can still be supportive if it has a quality spring system underneath the comfort layers. A firm mattress can lack support if it's just a dense block of cheap foam.

How to Choose Your Firmness

Consider Your Sleep Position

  • Side sleepers: Medium to medium-firm (5-7). Need cushioning for shoulders and hips.
  • Back sleepers: Medium-firm to firm (6-8). Need consistent support along the spine.
  • Stomach sleepers: Firm (7-8). Need to prevent the midsection from sinking.
  • Combination sleepers: Medium-firm (6-7). Versatile for position changes.

Consider Your Body Weight

  • Lighter sleepers (under 60kg): Often prefer softer options as they don't compress the mattress as much.
  • Average weight (60-90kg): Medium to medium-firm typically works well.
  • Heavier sleepers (over 90kg): Usually need firmer options for adequate support.

Consider Your Partner

If you share a bed with someone of different weight or sleep preferences, medium-firm is usually the best compromise.

The "Firm is Better" Myth

Many people believe firmer mattresses are better for your back. This isn't necessarily true.

Research shows medium-firm mattresses often provide the best outcomes for back pain. Too firm can create pressure points; too soft can allow the spine to curve.

"Orthopaedic" is a marketing term, not a medical classification. An "orthopaedic" mattress isn't automatically better for your back.

Firmness Changes Over Time

New mattresses often feel firmer initially. Most soften slightly during the first 30-60 days as materials break in. This is normal.

If your mattress feels too firm at first:

  • Give it 2-4 weeks to settle
  • Consider a mattress topper if still too firm

If too soft from the start, this is unlikely to improve.

Testing Firmness

If possible, try before you buy. But remember:

  • A few minutes in a showroom isn't the same as eight hours sleeping
  • You need 2-4 weeks to truly adjust to a new firmness
  • Trial periods let you test at home properly

Our Firmness Options

The Nexa range is designed around the most popular firmness levels:

  • Nexa Hybrid Lite: Medium-firm (6.5/10) — versatile, suits most sleepers
  • Nexa Hybrid Deluxe: Medium-firm (7/10) — slightly firmer, excellent support
  • Nexa Plush 2000: Medium (6/10) — more cushioning, ideal for side sleepers

Conclusion

The "right" firmness is personal and depends on your sleep position, body weight, and preferences. Medium-firm works for most people, but don't assume firmer is automatically better.

Explore our mattress range to find your ideal comfort level.

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