Choosing a mattress without going by price
The main criterion is that the spine stays aligned in your habitual sleeping position, which depends on body weight and on whether you sleep on your side, back or front rather than on the price bracket of the mattress.
gelisted editorial team · Updated 15 August 2026
The short version
- A mattress lasts 8 to 10 years.
- Test it for at least 10 minutes in your real sleeping position.
- The legal warranty is 3 years from delivery.
- A worn base ruins the best mattress.
You spend about 3,000 hours a year on it and choose it in 10 minutes standing up. Spending those 10 minutes lying down changes the outcome entirely.
The right firmness
It follows weight and position. A light person sleeping on their side needs the mattress to let shoulder and hip sink so the spine stays straight, which means medium or medium soft. A heavier person needs greater firmness to avoid sinking too far. And anyone sleeping on their back or front needs more firmness than a side sleeper of the same weight.
| Weight | On the side | On back or front |
|---|---|---|
| under 60 kg | medium soft | medium |
| 60 to 80 kg | medium | medium firm |
| 80 to 100 kg | medium firm | firm |
| over 100 kg | firm | firm reinforced |
| Usual service life | 8 to 10 years | |
| Legal warranty | 3 years | |
| Minimum testing time | 10 minutes | |
| Rotate head to foot | every 3 months |
Testing it properly
Lying down in the position you actually sleep in, not perched on the edge. For at least 10 minutes, because the first 30 seconds only tell you about the top comfort layer. With the pillow you use at home or one of similar height. And with someone looking from the side to see whether the spine stays straight or curves, which is impossible to judge from inside.
What almost nobody considers
The base. A slatted base with broken slats, or a sagging divan, deforms any new mattress within months and voids the warranty in many cases. And in the island climate, with high relative humidity through much of the year, ventilation from below matters: a mattress on a closed upholstered base needs airing more often than one on slats.
Rotating the mattress head to foot every 3 months spreads the wear and noticeably extends its life.
When to replace it
At 8 to 10 years as a reference, and sooner if a permanent impression of more than 2 or 3 centimetres appears, if you wake with discomfort that fades during the day, or if you sleep better away from home. The legal warranty runs 3 years from delivery and covers manufacturing defects, not normal wear and not a firmness chosen badly.
Frequently asked
+What firmness do I need?
The one that keeps your spine aligned in your habitual position, according to your weight and how you sleep.
+How long should I test it in store?
At least 10 minutes lying in your real position, with a pillow of similar height to yours.
+How long does a mattress last?
Eight to ten years, sooner if a permanent impression or morning discomfort appears.
+Does the base matter?
Considerably. A worn base deforms a new mattress within months and can void the warranty.
+What does the warranty cover?
Manufacturing defects for 3 years from delivery, not wear or a badly chosen firmness.
Sources
- 1Boletín Oficial del Estado, BOE (August 2026)
- 2Ministerio de Sanidad, Gobierno de España (August 2026)