Firmness
Mattress Firmness for Back Sleepers
Back sleepers often look for a balance between surface comfort and resistance to excessive sinking.
Firm is not automatically better
An extra-firm surface can feel uncomfortable to some back sleepers, while a very soft design can allow more sink than they prefer. Use a known mattress as your baseline.
Compare full construction
Coils, zoning, foam density and thickness all affect how a mattress carries weight beyond its firmness label.