How to Choose a Mattress: Firmness, Type and Position Explained
The three questions that decide 90% of the choice, with the measurements from our ten-mattress test.
1. How do you sleep?
Side sleepers need the shoulder to sink: our pressure mat favoured medium beds (5–6.5) with a thick comfort layer — Helix Midnight, Nectar, Purple, Tempur-Adapt. Back sleepers need the hips held: 6–7.5, and the Saatva's lumbar zone measured best. Stomach sleepers need firm (7+) so the hips do not sag: Saatva, Avocado, DreamCloud.
2. Do you sleep hot?
Foam holds heat. In our 30-minute heated-pad test the Purple grid and the coil hybrids (Helix, Avocado, Saatva) stayed within 2°F of room temperature; Nectar, Tempur-Pedic and Zinus ran 6–9°F warmer.
3. Do you share the bed?
Foam isolates motion (Nectar and Tempur-Pedic best); innersprings transfer it (Saatva most). Couples with different needs can look at zoned or dual-firmness options, or accept a medium hybrid like the Helix as the compromise.
Then: weight, edge, trial
Over 230 lb, choose a hybrid or innerspring. If you sit on the edge to dress, check the edge score. And use the trial: every mattress here can be returned, and the Nectar, DreamCloud, Saatva and Avocado give you a full year.
» See the full rankings: Best Mattresses of 2026, Best Mattress for Side Sleepers in 2026, Best Mattress for Back Pain in 2026 .