Sheets, towels, iron
When to Replace a Mattress
7–10 years is a range, not a law. Replace when sag is over 2.5–4 cm, you wake more sore than you went to bed, or the foam has crumbled. A topper is a delay, not a resurrection.
Updated 27 Aug 2026 · 6 min read · when to replace a mattress
Sag, not birthdays
Strip the bed. Lay a straightedge across the middle. If the gap under it is more than about 3 cm in the person-shaped well, the core has packed out. Body impressions under 1.5 cm can be normal in foam. Springs that you can map with a palm are done.
Pain that appears only at home, a partner rolling into your valley, or a smell that survives cleaning a mattress: those are replacement cues. Age alone is not. A well-made 9-year latex mattress can beat a 3-year budget foam.
| Construction | Typical honest life | Common death |
|---|---|---|
| Budget foam, 18–20 cm | 5–7 years | Crumble, permanent well |
| Innerspring / thin pillow-top | 7–8 years | Coil feel, edge collapse |
| Hybrid, decent foams | 8–10 years | Comfort layer gone, coils still live |
| Latex, solid | 8–12 years | Slow sag, then oxidation |
What is not a reason to replace
A stain you can isolate with a protector. A 7-year anniversary email from a brand. A pillow that died. A room that is 24C. Fix those first. A topper can buy 12–18 months on a mattress that is slightly too firm and still structurally sound. It cannot unsag a hammock.
When you do replace, do not copy the old mistake
Re-read firmness against how you actually sleep now, not how you slept at 25. Measure depth for sheets (25 cm cores want 35–40 cm pockets). Budget a protector from night one. Recycle the old one properly; do not store it in a shed “for guests” unless you would sleep on it.
Questions, answered
- Can I flip a mattress to double its life?
- Only if it is a true flippable innerspring with two comfort faces. Most modern foams are one-sided. Rotating head-to-foot every 3–6 months is the real maintenance.
- The trial said 100 nights and I am on night 40, still sore.
- Foam can take 30 nights to settle. Persistent morning pain at day 45 is a return, not a character test.
- Is a 15-year mattress ever still good?
- Latex, maybe, if sag is under 2 cm and you sleep well. Most 15-year sprung mattresses are furniture at that point.
