How to Choose a Mattress

Start with how you sleep

Before mattress type or price, the single most useful thing to know is your usual sleeping position. It decides how much support and cushioning your body needs, and it quietly rules out a lot of options.

• Side sleepers need a little give. Your hips and shoulders are the widest points and they need to sink in slightly so your spine stays level. Too firm and you get pressure and dead arms. Medium to medium-soft usually suits.
• Back sleepers want support with just enough cushioning to fill the curve of the lower back. Medium to medium-firm is the sweet spot.
• Front (stomach) sleepers need it firmer, so the hips don’t sink and arch the lower back. Go medium-firm to firm.
• Combination sleepers who move around are best served by a responsive medium: supportive enough for your back, forgiving enough for your side.

The main types, in plain English

Almost every mattress you'll see is one of five constructions. None is 'best' outright; they simply trade comfort, support, temperature and price differently.

Memory foam

Foam that softens with body heat and moulds to your shape, then slowly springs back. It cushions pressure points well and absorbs movement, so a restless partner barely registers. The trade-offs: it can sleep warm, and cheaper foam can feel like it holds you in place. Best for side sleepers and lighter sleepers who like a hugged feeling.

Pocket sprung

Individual springs, each sewn into its own fabric pocket, so they move independently and support your body point by point. That independence is why they isolate movement well and don't roll you together in the middle. More pockets generally means finer, more responsive support. It's a safe, breathable all-rounder, and the type most premium mattresses are built on.

Hybrid

A pocket-sprung core topped with foam (memory, or a cooler gel or latex foam). The aim is the best of both: sprung support and airflow underneath, pressure relief on top. Usually a touch firmer and cooler than all-foam. A sensible default if you can’t decide, and a strong shout for anyone who likes foam but overheats on it.

Latex

Springier and more buoyant than memory foam: it supports and relieves pressure but pushes back rather than hugging, and it sleeps cool and lasts a long time. Natural latex is durable and breathable, though it carries a premium price and is heavy to move.

Open coil (continuous / bonnell spring)

The traditional single-wire spring unit. It’s cheap, light and fine for a spare room, a child’s bed or occasional use, but the springs are linked, so it supports you as one surface and passes movement across the bed. Not the one for a bed you sleep on every night for years.

Firmness is personal, not a quality score

Firmness ratings (soft, medium, firm) describe feel, not quality. A 'firm' mattress isn't better made than a 'medium' one; it just suits a different sleeper. And the labels aren't standardised: one brand's medium is another's firm. Treat them as a rough guide, then weigh your own sleeping position and build over the marketing word.

• Heavier sleepers sink further, so they generally want one step firmer than the label suggests.
• Lighter sleepers press in less, so a mattress marked firm can feel firmer still to them. Size down on firmness.
• If you’re unsure, a medium or medium-firm is the safest bet and the easiest to fine-tune later with a topper.

What pocket counts and "layers" really tell you

Product names love a big number: 3000 pockets, 5-zone support, seven layers. Some of it matters, a lot of it is there to sound expensive. Here's what to actually weigh.

• Pocket count is measured on a king size, so compare like for like. A "1000 pocket" double has more springs per square metre than a "1000 pocket" super king. Beyond roughly 1000 to 2000, more pockets give diminishing returns in feel, and the fillings on top often matter more.
• Zoned support (firmer under the hips, softer at the shoulders) is useful for back and heavier sleepers, less noticeable for lighter ones.
• Natural fillings (wool, cotton, cashmere) breathe and wick moisture better than synthetic, which is why they cluster at the premium end. It’s a real comfort and longevity difference, not just a spec-sheet flourish.
• Layer counts on their own tell you little: three good layers beat seven cheap ones. Read what the layers are, not how many.

Getting the size right

Buy the biggest that fits the room, leaving a clear walkway around the bed and space to open wardrobe doors. As a rule of thumb, a couple sleeps best with the same width each as they’d have alone, which is why so many couples on a standard double wish they’d gone up a size. These are the standard UK sizes:

• Single, 90 × 190 cm (3ft). One adult, children, box rooms and bunk beds.
• Small double, 120 × 190 cm (4ft), also called a "three-quarter". Good for a solo sleeper who wants room to spread, or two at a squeeze in a smaller room.
• Double, 135 × 190 cm (4ft6). The UK default for couples and the most-stocked size, so you get the widest choice and the keenest prices.
• King, 150 × 200 cm (5ft). More width and 10 cm more length, worth it for taller sleepers and couples with the floor space.
• Super king, 180 × 200 cm (6ft). The luxury option. Check it fits up your stairs and through doorways before you buy.

Trials, warranties and delivery

You can't really judge a mattress in five minutes lying on it in your coat. It takes a few weeks for your body to adjust and for the mattress to settle, which is why the small print matters as much as the spec.

• Sleep trials. Many bed-in-a-box brands offer 100 nights or more to try it at home and send it back if it’s wrong. Check whether returns are actually free, and how collection works, before you rely on it.
• Warranty. Five years is common, ten or more at the premium end. It covers manufacturing faults such as premature sagging, not a change of heart. That’s what the trial is for.
• Delivery and disposal. Check the cost, the lead time, and whether they’ll take your old mattress away. Rolled, vacuum-packed mattresses need 24 to 72 hours to fully expand, so don’t judge one the night it arrives.
• Off-gassing. New foam can carry a faint chemical smell for a day or two. It’s normal and airs out, so give the room some ventilation.

How much should you spend?

You don’t need to spend a fortune, but a mattress is one case where the cheapest option is usually a false economy: you’ll replace it sooner and sleep worse in the meantime. A good one should last around 7 to 10 years, so it’s worth thinking in cost-per-night. As a rough guide for a double:

• Under £300, for spare rooms, kids, first flats and occasional use. Plenty of honest foam and entry pocket-sprung mattresses do the job.
• £300 to £500, the sweet spot for an everyday bed: proper pocket springs or a decent hybrid that’ll last.
• £500 and up, for natural fillings, higher pocket counts and hand-finished build, where the difference shows over years rather than nights.

Prices for the same mattress can vary a lot between retailers, and mattresses are almost always 'on sale', so a sale price is only a deal if it's actually below what others charge. That's the bit we do: we track live prices across the UK retailers we list so you can compare before you buy. For a shortlist to start from, see The Best Double Mattresses, or browse every mattress we track and filter by size, type and price.