How Firm Should Your Mattress Be?
Firmness is how hard or soft a mattress feels when you first lie on it. It’s different from support, which is how well the bed keeps your spine aligned. The right firmness depends mainly on two things: how you sleep and how much you weigh.
Firmness by sleeping position
- Side sleepers: 4–6.5/10. Softer surfaces let shoulders and hips sink in.
- Back sleepers: 5.5–7.5/10. Medium-firm supports the lower back.
- Stomach sleepers: 7–9/10. Firm surfaces stop the hips sinking.
- Combination sleepers: 5–7/10, ideally with some bounce.
Adjust for body weight
Heavier people sink further into any mattress, so a bed feels softer to them. If you weigh over 230 lb, add about one point to the targets above. If you weigh under 130 lb, subtract about one point.
Still unsure?
Take our mattress quiz to get personalised recommendations based on our test data.
FAQs
What is medium-firm on the firmness scale?
Medium-firm is usually about 6.5–7 out of 10. It’s the most popular firmness because it suits back, combination and many side sleepers.
Can a mattress be too firm?
Yes. A mattress that’s too firm can create pressure points at the shoulders and hips, especially for side sleepers.
What is the most popular mattress firmness?
Medium-firm, around 6.5 out of 10, because it suits back, combination and many side sleepers.
Do mattresses get softer over time?
Yes. Most mattresses soften slightly over the first few weeks as the comfort layers break in.
