Fix your mattress · Updated September 2026
Mattress Too Soft: How to Make It Firmer
A mattress that feels too soft usually means your hips are sinking deeper than your shoulders, which pulls your spine out of line overnight. The good news: softness is partly about the mattress and partly about everything under and over it, so there are real fixes short of buying a new bed. They are ranked below from free to most expensive, which is also the order you should try them.
First, rule out the break-in period
A new mattress — especially memory foam — often feels softer after the first few weeks than it did in the first nights, because the foams relax with use. If the mattress is under a month old and your trial period is still running, give it three to four weeks of regular sleep before deciding it is genuinely too soft.
If the mattress is older and has gradually become softer, that is wear, not break-in. The fixes below still help, but a worn-out comfort layer can only be masked, not restored.
Check what is underneath it
A mattress reflects its foundation. Slats that are too far apart, a sprung base, or a worn box spring all let the mattress sag between supports, which reads as softness even when the mattress itself is fine. A solid platform or closely spaced slats make the same mattress feel noticeably firmer.
This is the cheapest firming fix there is, and it is the one most people skip. Pull the mattress off, press along the base, and look for flex, gaps or broken slats before blaming the mattress.
- Slats should be rigid and closely spaced — check the mattress maker's specified maximum gap.
- Replace a sagging or sprung base with a firm platform or bunkie board.
- On the floor temporarily is a useful test: if the mattress feels firmer on the floor, the base is the problem.
Rotate it and warm the room
Rotating the mattress 180 degrees moves the most-compressed zone away from your hips. It does not repair wear, but on a mattress with uneven softening it buys meaningful time.
Memory foam also firms up in a cold room and softens as it warms. If your bedroom runs warm, cooling the room slightly makes a foam mattress feel firmer; if it runs cold, the same mattress can feel harder than intended.
Add a firm topper
Toppers are usually sold to soften a bed, but firm latex and dense foam toppers exist for exactly this problem. A firm topper adds a supportive layer above the tired one, raising the effective firmness of the whole surface without replacing the mattress.
This is the most effective paid fix, and it is reversible. What it cannot do is fix a mattress with a deep sag — a topper laid over a crater takes the shape of the crater.
When replacement is the honest answer
If the mattress has a visible sag, if you roll towards the middle, or if the softness comes with morning aches that fade as the day goes on, no topper or base will restore it. Comfort layers do not un-compress. At that point the money is better spent towards a replacement than on fixes.
A mattress can be too soft, too firm or worn out, and fixing that is worth doing. But pain that persists for weeks, pain that wakes you at night, or pain with numbness or tingling is not a furniture problem — that is worth raising with a clinician.