If you're paying hundreds for a mattress, you'd expect it to last a few years. We recommend you replace your mattress every eight to 10 years, but nearly half of the Which? members we surveyed (47%) kept theirs for longer*.
Read on for signs you need to replace your mattress and to get tips on how to extend the life of your new mattress.
Four signs your mattress needs replacing
1. It’s uncomfortable
Comfort is a big deal when it comes to getting a decent night's sleep. In our mattress survey, comfort was cited as one of the main reasons Which? members ditched their old mattress. One third bought a new mattress because it felt comfortable when trying it out in the shop*.
Comfort is subjective though, which is why it's so hard to pin down one mattress that suits everyone. What works for you may not work for someone else.
To inform our reviews, we put each mattress through our key body support tests. We also measure pressure distribution for each mattress. These tests are designed to reveal if you'll sink into a mattress in one spot more than another - this could aggravate existing back issues or cause problems in other places.
If you already have back pain, or other aches and pains, a new mattress won't solve the underlying issue - always get it checked out by a medical professional instead.
2. It’s sagging or sinking in places
Is your mattress sagging or has it started to soften? Are you sleeping in a dip? As a mattress ages, its layers can compress, causing it to sag or soften. However, you may not notice it as you become used to sleeping on it over the years.
For our mattress durability tests, we mimic eight to 10 years of use by repeatedly squishing mattresses with a large, heavy roller to compress them repeatedly. We run our key body support tests before and afterwards. The resulting data can pick up how compressed a mattress becomes and will highlight any reduction in support for the three key sleeping positions (front, side and back).
Be aware that if your old mattress is soft or sagging, it can also affect how you feel about your new one - you could find a new mattress feels a lot firmer than what you're used to.
3. It’s more than 10 years old
The NHS recommends seven to nine hours' sleep per night; assuming 10 years of use and seven hours sleep a night, this equals around 22,550 hours of use for your poor mattress.
That's not taking into account any other use, such as working from bed, or when you're ill or recovering from an operation where you are likely to be in bed for longer periods.
That means a really old mattress can be a pretty grim place to sleep.
Plus, spills and stains can accumulate over time...
See4. It’s dirty, smelly or there are signs of wear and tear
The National Bed Federation says that by the time your mattress is seven years old, it will have absorbed a whole bathful of body moisture, thanks to how much you sweat each night.
It will also accumulate around 450g of dead skin - which isn't ideal if you are sensitive to dust mites.
If you notice any damage to the foam, springs poking out or stitching coming loose, it's probably time to consider a replacement.
How to make your new mattress last longer
There are plenty of things you can do to help make your mattress last longer.
Reading the care instructions is always the first place to start - otherwise you could inadvertently void the mattress warranty or cause damage by using it incorrectly or not looking after the mattress as recommended.
Regular cleaning will no doubt help keep it in good condition, and airing your mattress regularly as well as vacuuming it will help stop moisture lingering and dust accumulating.
On a more practical basis, avoiding eating and drinking in bed and stopping pets or kids jumping about on your mattress will all help to keep it in good condition.
* Based on a survey of 3,530 mattress-owning Which? Connect Panel members in October 2023source https://www.which.co.uk/news/article/how-often-should-you-replace-your-mattress-anUQl9j8hFBl