How to Choose a Mattress: UK Buying Guide (2026)
Reviewed by the Onlineand.direct bed team — UK-made mattresses, free 3-day delivery.
In short: The right mattress comes down to three things — your sleeping position, your body weight, and your firmness preference. Side sleepers and lighter people suit softer-to-medium mattresses that cushion the shoulder and hip; back and front sleepers and heavier people need medium-firm to firm support to keep the spine aligned. Pocket-sprung and hybrid mattresses suit most people; memory foam adds pressure relief and motion isolation.
A mattress is the one piece of furniture you use for a third of your life, so it's worth getting right. This guide cuts through the jargon — spring types, firmness, pocket counts and sizes — and tells you what actually matters for how you sleep.
Mattress types explained
- Pocket sprung: individual springs in fabric pockets move independently, supporting the body precisely and reducing roll-together. The all-round favourite.
- Memory foam: moulds to your body for pressure relief and excellent motion isolation (great if a partner moves at night). Can sleep warmer.
- Hybrid: pocket springs plus a foam comfort layer — support and pressure relief together. The best of both for most sleepers.
- Open coil (Bonnell): one connected spring unit — budget-friendly and firm, but less precise support.
Firmness — by sleep position & weight
| You sleep… | Lighter build | Average build | Heavier build |
|---|---|---|---|
| On your side | Soft–Medium | Medium | Medium–Firm |
| On your back | Medium | Medium–Firm | Firm |
| On your front | Medium–Firm | Firm | Firm |
Side sleepers need the shoulder and hip to sink in slightly to keep the spine straight; back and front sleepers need more support to stop the hips dipping. Heavier bodies need a firmer feel to get the same support.
UK mattress sizes
| Size | Dimensions |
|---|---|
| Small Single | 2'6" × 6'3" (75 × 190 cm) |
| Single | 3'0" × 6'3" (90 × 190 cm) |
| Small Double | 4'0" × 6'3" (120 × 190 cm) |
| Double | 4'6" × 6'3" (135 × 190 cm) |
| King | 5'0" × 6'6" (150 × 200 cm) |
| Super King | 6'0" × 6'6" (180 × 200 cm) |
Does pocket count matter?
Up to a point. More pockets (say 1,000 to 2,000) generally means more precise support and a more luxurious feel — but spring quality, gauge and the comfort layers matter just as much. Beyond about 2,000 in a domestic mattress, gains are marginal. Don't buy on pocket count alone.
How to choose — a quick checklist
- Position & weight — use the table above.
- Sleeping partner? — pocket sprung or memory foam reduces disturbance.
- Sleep hot? — favour pocket sprung or hybrid over all-foam.
- Aches & pains? — medium-firm support with a pressure-relieving comfort layer.
- Allergies? — removable, washable covers help.
Signs you need a new mattress
Sagging or visible dips, waking stiff or sore, springs you can feel, or simply 7–8 years of use. A mattress past its best undoes the support you paid for.
Mattress + base compatibility
- Ottoman / divan (solid base): any mattress works; pocket sprung or hybrid recommended. See the ottoman and divan guides.
- Slatted frame (metal or wooden): keep slats 7cm apart or less; pocket sprung and hybrid suit slats well; avoid thin all-foam that can sag between slats.
Our mattress range
UK-made, with free 3-day delivery and Klarna:
- Memory Foam Pocket-Spring Hybrid (DELU-POCKET) — from £249
- 2000 Pocket Spring Mattress (BUCK-2000) — medium-firm, from £410
Shop mattresses → · Free 3-day UK delivery · Pay in 3 with Klarna
Frequently asked questions
What mattress firmness do I need?
Match it to how you sleep and your weight: side sleepers softer-to-medium, back/front sleepers medium-firm to firm, heavier bodies a step firmer.
Pocket spring vs memory foam vs hybrid?
Pocket spring = precise, breathable support; memory foam = pressure relief and motion isolation but warmer; hybrid = both, and the best all-rounder.
What does pocket count mean?
The number of individual springs. More can mean more precise support, but spring quality and comfort layers matter just as much — don't buy on the number alone.
How often should I replace a mattress?
Typically every 7–8 years, or sooner if it sags, you wake sore, or you can feel the springs.
Best mattress for back pain or side sleepers?
For back pain, medium-firm support with a pressure-relieving comfort layer (a hybrid). Side sleepers usually prefer soft-to-medium to cushion the shoulder and hip.
What size mattress do I need?
Match your base size (see the UK size table). Couples are usually most comfortable on a King or Super King if the room allows.