How long does a mattress last, and the six signs yours is done

The trade answer is seven to ten years. The honest answer is that it depends almost entirely on what the mattress is made of, and most people are sleeping on one that has quietly stopped doing its job. Here is what wears out, what decides the lifespan, and how to check yours.

Where the seven-year rule comes from

The Sleep Council (now the Sleep Charity) ran a "replace every seven years" campaign for years, and it stuck. It is a reasonable average across the market. It is also an average of a £150 mattress that is finished in three years and a £1,500 one that is fine at fifteen, so it does not tell you much about yours.

What actually wears out

Mattresses do not usually break. They soften, unevenly.

The comfort layers go first. Foam fatigues: the cell walls lose their spring and the foam stops recovering fully. Where you lie every night, it recovers less than at the edges, and you get a body impression. Low-density foams (under 40 kg/m³) do this in two or three years. Good memory foam (55 kg/m³ and up) and latex take eight to twelve.

Springs lose height, slowly. A decent pocket spring in 1.8 mm wire loses a little height over ten years, evenly. Cheap open-coil units lose it faster and start to creak. A spring unit is rarely the reason a mattress is replaced, unless the edge collapses.

Edges collapse. If the border is a soft foam rail, the side you sit on every morning goes first, and the mattress starts to feel narrower than it is.

Fillings compress. Polyester wadding in quilted covers flattens in a couple of years. Wool and cotton felt settle and then stay. This is why old traditional mattresses are firmer than they were new but still level, and old cheap ones are dished.

What decides the lifespan

The six signs it is done

Check tonight. It takes two minutes.

1. A dip you can see. Take the bedding off and look across the surface at eye level against the light. A hollow where you sleep of more than about 2.5 cm means the comfort layer has gone.
2. You roll towards the middle, or towards your partner, without meaning to.
3. Your hips drop. Lie on your side, hand flat under your waist: if there is a gap, your hips are sinking lower than your shoulders and the support has gone.
4. You wake stiff and it eases in half an hour. Stiffness that goes away once you are up and moving is usually the bed, not you.
5. You slept better somewhere else. A hotel, a friend's spare room. If a random bed beats yours, yours is the problem.
6. The edge gives when you sit on it, or it creaks when you turn over.

Age alone is not on the list. A ten-year-old mattress with none of these is fine. A three-year-old one with two of them is not.

Making the next one last

• Buy on density and gauge, not on the count or the brand. Ask for the numbers in writing.
• Rotate it head to toe every three months for the first year, then twice a year.
• Use a breathable protector from day one.
• Check the base before the mattress arrives: slats close together, a centre rail on a king, nothing broken.
• Do not let anyone stand on it. Springs and edges hate point loads.

Our guarantee, and why it is ten years

Every Chapter mattress carries a ten-year guarantee on the build: a visible dip of more than 2.5 cm not caused by the base, a spring failure, or stitching. We can offer that because the foams are specified by density on every layer, from 50 kg/m³ memory foam on the entry build up, and because the springs are 1.8 mm or heavier with a rail or steel edge. The spec is on every product page. A mattress lasts eight to ten years, and life moves on; when it is time, the chapter you need next will probably not be the one you have now.

The short version

• Seven to ten years is an average. Density and gauge decide where you fall.
• Foams soften unevenly; that is what "worn out" means.
• Look for a dip, a roll, a gap under your waist, morning stiffness, a better night elsewhere, a soft edge.
• Buy on numbers, rotate it, protect it, check the base.