Firmness is not support
Firmness describes how hard or soft the surface feels. Support describes how the mattress manages your body over time. A softer mattress can still be supportive; a hard mattress can still be a poor match.
Start with your dominant position
| Position | Common starting direction | Watch for |
|---|---|---|
| Side | Medium to medium-soft | Pressure at shoulder and hip |
| Back | Medium to medium-firm | Excess sink under the pelvis |
| Stomach | Medium-firm to firm | Midsection sinking too deeply |
| Combination | Responsive medium range | Difficulty changing position |
Then adjust for your actual response
Body weight distribution, frame, injuries, sensitivity, bedding, and personal preference can move the answer in either direction. Treat firmness labels as broad categories, not standardized measurements across brands.
A safer question
Instead of asking “What firmness should I buy?” ask: “Where do I feel pressure, where do I sink, and how easily can I change position?”
Turn the guide into a shortlist.
Answer three questions and get a sensible product page to start with.
Use the fit finder →