How to Choose a Mattress (UK Decision Guide)

What should I decide first when I choose a mattress?

Pick the build type first. Then match support to body weight. Then pick how the top feels for the way you sleep. Then lock UK size in centimetres and check the bed base. Soft, medium and firm labels mix those steps. Split them or you compare unlike things.

This page is a decision order, not a brand list. We have not slept on any mattress here. Use it to ask better questions in a shop or online listing. The full pre-purchase list is before you buy a mattress.

Which mattress type should I start with?

Start with how the core holds you up. Pocket sprung uses steel coils in fabric bags. Open coil links coils into a grid. Memory foam moulds slowly with heat. Latex is bouncier foam. A hybrid is springs plus a thick foam or latex top.

Type	Good starting point	Skip it if
Pocket sprung	Springs in fabric bags. Often kinder for couples. Air can move through.	You need a very low profile packed in a box and cannot accept spring feel.
Hybrid	Springs plus a thick foam or latex comfort layer	Your base has wide slat gaps the foam maker does not allow.
Memory foam	Slow moulding. Can cut partner movement.	You sleep hot and dislike a “hug” feel.
Latex	Bouncier foam. Often cooler than classic memory foam.	You want the slow melt of memory foam.
Open coil	Linked springs. Usually lower cost.	Partner movement bothers you.

Overview of all types: mattress types explained.

How do I match support to my body weight?

For pocket sprung and hybrid beds, spring tension (how stiff the springs are) should suit your weight. It is not the same as the word “soft” on the ticket. A heavy sleeper on light tension can bottom out. A light sleeper on heavy tension can feel perched.

For foam beds, read density and ILD as two numbers. Thickness alone is not support. See spring tension vs comfort feel.

We do not publish a kilogram-to-tension chart. Makers use different wires and foams. Ask the maker which tension band they intend for your weight.

How should sleep position change the top feel?

Side sleepers often need more give at shoulders and hips so the spine can stay nearer a straight line from the side. Back sleepers often want a flatter lumbar feel. Stomach sleepers often need less sink so the hips do not drop.

That is surface feel, on top of the support you already picked. Use firmness and sleep position plus the side, back and stomach guides. This is not medical advice.

What size and base must I lock before I pay?

Size first, in centimetres. A UK Double is 135 × 190 cm. A King is 150 × 200 cm. A Super King is 180 × 200 cm. Names are not enough if frames or sheets come from the EU or US. See UK standard sizes.

The base can void a warranty if slat gaps are too wide or the foundation is wrong. Foam-heavy mattresses often need a firm platform or slats with a small gap — makers often quote about 7 cm as a maximum, but the warranty leaflet wins. See base compatibility and how to choose a bed base.

Measure stairs and doors. See footprint and access.

What if two people disagree?

Different body weights or different likes of plushness point to zip-and-link or to a zoned / hybrid build. Motion transfer is a separate question — see motion isolation. A topper will not split two support needs honestly.

What should I ignore in the shop script?

Ignore “orthopaedic” as a medical claim — see what orthopaedic means here. Ignore spring count without a size. Ignore matching quizzes as proof — they are starting points, see how mattress matching quizzes work. Ignore “best mattress 2026” lists on this site: we do not write them.

Ask construction questions instead: questions to ask in a bed shop.

What should I write down in the shop?

Write the support system. Write tension or density for your weight. Write count in this UK size if the bed is sprung. Write width × length in centimetres. Write the approved base. Write trial start and warranty impression depth.

The National Bed Federation says UK size names are industry practice, not a legal Act. IKEA UK lists extra centimetre lines beside standard UK sizes. Both notes were checked on 28 August 2026. A “King” on two tickets can still be two plans.

Take questions to ask in a bed shop with you. The longer checklist is before you buy a mattress.

What happens after I buy?

Plan trial small print, warranty small print and legal refund rights before delivery day. A rolled mattress needs expansion time — rolled mattress expansion. Then break-in and rotate or turn.

Pillow, duvet TOG and a protector change the night as much as the core. Start with how to choose a pillow and how to choose a duvet.

Related BedGuide entries

• Before you buy a mattress
• What’s inside a mattress
• Budget vs premium mattress
• Upholstery depth and GSM
• Edge support
• Learn: buy your first mattress
• Answers hub