Mattress Firmness Guide: How to Choose Without Guessing

Firmness is subjective, but sleep position and body weight give you a useful starting range. The goal is enough cushioning where you load the mattress without letting heavier areas sink excessively.

The 1–10 scale

Many publishers use a 1-to-10 firmness scale, with 1 softest and 10 firmest. Brands do not share one standardized measuring instrument, so compare within a brand first and treat cross-brand numbers as approximate.

Side sleepers

Side sleepers concentrate pressure at the hips and shoulders and often prefer more cushioning. Sleep Foundation's guidance ranges softer for lighter side sleepers and firmer as body weight increases.

Back sleepers

Back sleepers often do well around medium to firm because they need enough contouring for comfort while keeping the torso supported. Heavier back sleepers generally need a firmer surface than lighter sleepers.

Stomach sleepers

Stomach sleepers often prefer medium-firm to firm mattresses because excessive sinkage through the midsection can feel uncomfortable. Again, body weight changes how much the surface compresses.

Combination sleepers

People who change positions usually benefit from a responsive mattress that is easy to move on and a middle-of-the-road firmness unless one position dominates.

Use your current bed as evidence

Your existing mattress is useful data. If it creates pressure at shoulders/hips, compare softer or more contouring options. If your hips sink too far or movement feels difficult, compare firmer or more responsive options.

Sources & further reading

Specifications and policies are checked against manufacturer pages; general mattress guidance uses independent educational sources where appropriate.

• Sleep Foundation firmness guide
• Sleep Foundation mattress shopping