Buying Guide
Mattress Firmness Guide UK
The right firmness depends on sleeping position and body weight: side sleepers generally do best on medium to medium-soft mattresses, back and stomach sleepers on medium-firm to firm, and heavier body types on firmer support to prevent sinking. PrimeSleep offers pocket sprung, memory foam, hybrid and orthopaedic builds across that full firmness range.
Firmness by sleeping position
- Side sleepers — medium to medium-soft, so the mattress cushions the shoulder and hip while keeping the spine level.
- Back sleepers — medium-firm, giving even support along the lower back without excess sinkage.
- Stomach sleepers — firm, to stop the hips dropping and the lower back arching overnight.
- Combination sleepers — medium, which adapts reasonably well across positions through the night.
Firmness by body weight
Heavier body types generally need a firmer mattress or a deeper pocket-sprung/hybrid build to avoid sinking too far into the surface, while lighter body types often feel a genuinely firm mattress as uncomfortably hard and benefit from a medium or medium-soft feel.
Which PrimeSleep range fits which need
- Orthopaedic — firmer, targeted support for back and joint concerns.
- Pocket sprung — classic supportive contouring, a solid all-round medium-firm choice.
- Memory foam and hybrid — pressure relief and motion isolation, typically medium to medium-firm.
Frequently asked questions
Which mattress type is best for back support?
Orthopaedic and firmer pocket sprung mattresses generally give the most consistent back support, since they resist excess sinkage at the hips and shoulders.
Can a mattress be too firm?
Yes — an overly firm mattress can create pressure points at the shoulders and hips, particularly for side sleepers and lighter body types.
Do I need a different firmness for a partner with different needs?
A medium-firm mattress is usually the most workable shared compromise; some ranges also allow choosing different tension or side-specific builds on request.