How to Buy a Mattress: The UK Buying Guide for 2026

Measure the internal dimensions of your bed frame rather than relying only on its description. Standard UK sizes differ from some European and US dimensions, and the external dimensions of a bed frame can be larger than the mattress it takes. Our UK mattress size guide lists the standard UK measurements. Also check the route from the front door to the bedroom before ordering a large or difficult-to-flex mattress.

Firmness labels are subjective and are not standardised between mattress brands. Side sleepers often prefer enough cushioning around the shoulders and hips, while back and front sleepers commonly look for a more supportive feel that limits excessive sinking. Body weight and personal preference also change how a mattress feels, so use labels such as medium or medium-firm as a starting point rather than an absolute measurement. Couples with different preferences can read our guide to choosing mattress firmness for partners.

Pocket-sprung mattresses use individually housed springs and can offer good airflow and a responsive feel. Memory foam contours more closely and is commonly chosen for pressure relief and motion isolation. Hybrid mattresses combine a spring core with foam or other comfort layers, aiming to balance responsiveness, cushioning and airflow. None of these constructions is automatically best: compare the specification and feel against your own priorities.

If you tend to overheat, compare airflow through the support core, the breathability of the comfort layers and the cover material rather than relying on a single 'cooling' label. Our hot-sleeper mattress guide explains the main construction differences. If you share a bed, motion isolation and usable sleeping space can matter just as much as firmness; see our best mattress for couples UK guide.

Compare prices for the same mattress size because headline prices are often size-dependent. Look beyond the purchase price at the trial period, returns conditions, warranty, delivery charges and any old-mattress collection service. A higher price does not automatically mean a mattress is better suited to you, so prioritise fit and specification before premium branding or marketing claims.

A home trial can be useful because a few minutes in a showroom cannot reproduce several nights of normal sleep. Check whether the trial has a minimum-use period, whether a mattress protector is required, how returns are collected and whether charges apply. Also confirm that your existing base meets the manufacturer's requirements for slat spacing, support and ventilation; an unsuitable base can affect both comfort and warranty terms.

Age alone should not determine whether you replace a mattress. Persistent sagging, permanent indentations or a noticeable loss of comfort and support are more useful signals. Our mattress replacement guide explains what to look for before deciding to buy a new one.