Buying a new mattress sounds straightforward until you start comparing firmness ratings, spring counts, foam types, pillow tops, sizes, guarantees and sleep trials. Two mattresses can look almost identical online yet feel completely different once you sleep on them.
That matters because comfort is not simply a question of choosing the softest or most expensive option. A mattress needs to suit your body, usual sleeping position, bed base, bedroom space and, when you share a bed, the needs of another sleeper. The National Bed Federation also points out that firmness descriptions are not standardised across manufacturers, so one brand’s “medium-firm” may not feel like another’s.
A better way to buy is to work through the decision in the right order: size first, support and comfort second, construction third, then the practical details such as your bed base, trial period, warranty and mattress care.
Get the Mattress Size Right Before Comparing Anything Else
Start with measurements rather than mattress materials. A great mattress in the wrong size is still the wrong mattress.
Standard UK mattress dimensions commonly include:
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Single: 90 x 190 cm, or 3ft x 6ft 3in
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Small Double: 120 x 190 cm, or 4ft x 6ft 3in
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Double: 135 x 190 cm, or 4ft 6in x 6ft 3in
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King: 150 x 200 cm, or 5ft x 6ft 6in
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Super King: 180 x 200 cm, or 6ft x 6ft 6in
Do not rely on the words “double” or “king” alone, particularly when replacing a mattress on an existing frame. The National Bed Federation warns that bed dimensions are not universally standardised and that imported European frames can use different measurements. Measure the actual sleeping platform before ordering.
Height is worth considering too. A standard double is only 190 cm long, while king and super king mattresses are normally 200 cm. The NBF recommends choosing a bed at least 10 cm longer than the tallest person using it, which can make a king particularly worthwhile for taller sleepers.
Also consider how the mattress will physically reach the bedroom. Measure narrow staircases, turns, doorways and loft access before buying a large or rigid mattress.
Adeline Waterson’s current mattress collection covers the main UK sizes from Single through Super King, allowing the mattress size to be matched directly with its corresponding bed frames.
Choose Support and Firmness Around the Person Sleeping on It
“Firm” and “supportive” are not the same thing. A mattress can be very hard without supporting your body particularly well, while a softer mattress can still provide good underlying support.
The goal is a surface that allows heavier areas of your body to settle appropriately without letting your body sink excessively. The National Bed Federation advises that correct support varies with height, weight, build and sleeping position; when lying on your side, the mattress should allow your body to remain reasonably aligned rather than forcing the hips and shoulders upwards or allowing them to collapse too deeply.
Match the Feel to Your Sleeping Position and Build
Side sleepers normally need enough cushioning around the shoulders and hips. A mattress that is excessively firm can create uncomfortable pressure in these areas, while one that is too soft may allow the midsection to sink too far. Back sleepers often prefer a slightly firmer feel, although personal comfort still matters more than following a rigid rule.
Body weight changes how the same mattress feels. A lighter sleeper may barely compress a firm mattress, whereas a heavier sleeper can experience the same mattress as noticeably softer. As a general principle, the NBF notes that heavier sleepers often require firmer mattress tension.
Be cautious with medical-sounding labels as well. An “orthopaedic” mattress is not automatically the correct choice for somebody with back pain. The NBF notes that the term does not follow a universal medical or mattress-industry standard and is often associated simply with a firmer product.
Persistent back pain should not be treated as a mattress-shopping problem alone. NHS guidance recommends seeking appropriate medical advice when back problems are severe, persistent or affecting daily life.
Think Differently When Two People Share the Bed
Couples should choose a mattress together whenever possible because two people can experience exactly the same surface differently. The NBF specifically recommends that both partners test the mattress rather than one person making the decision for both.
Movement is another consideration. Pocket springs operate more independently than traditional interconnected open-coil springs, allowing individual areas of the mattress to respond more locally to pressure. This construction can therefore be particularly useful when one partner frequently changes position during the night.
More room can also solve problems that mattress technology cannot. Moving from a double to a king gives both sleepers extra width, while a super king provides 180 cm across the mattress.
Compare What Is Inside the Mattress, Not Just the Marketing Name
Once you know your preferred size and general comfort level, compare construction.
Pocket-sprung mattresses contain springs that respond individually rather than being connected into one large spring system. This allows the mattress to react more closely to different areas of the body and can reduce the tendency for sleepers to roll together. Pocket-sprung mattresses are available in different tensions, so “pocket sprung” does not automatically mean soft or firm.
Bonnell or open-coil mattresses use rows of interconnected springs. They are a more traditional construction and commonly sit within budget to mid-market ranges. Because the springs work together more than pocket springs, the feel is generally less individually responsive.
Foam mattresses use foam layers of different densities and depths to create comfort and support. Memory foam responds to body shape and pressure, while other polyurethane or reflex-style foams can provide a more resilient feel. Foam construction is also commonly compatible with slatted and adjustable bases, although the manufacturer’s requirements should always be checked.
Then look at the comfort layers. Cotton is valued for breathability and moisture absorption, wool combines resilience with breathability, while memory foam provides a more contouring sensation. Mattress covers can also use moisture-management materials designed to move perspiration away from the sleeping surface.
Spring count should therefore be treated as one specification rather than a quality score. The spring design, wire, mattress tension and materials above the springs all affect how the finished mattress performs. The NBF also warns that a number included in a mattress model name does not necessarily represent its actual spring count.
This is why comparing complete specifications is more useful than choosing whichever mattress advertises the biggest number.
Adeline Waterson’s current collection illustrates the range of constructions available to UK shoppers, including pocket-sprung, Bonnell-spring, reflex-foam and pillow-top options across medium-soft, medium, medium-firm and firm classifications.
Check the Bed Base, Trial, Warranty and Care Before You Pay
A mattress does not operate independently of the furniture underneath it. Slatted bases, solid platforms and divan bases can give a mattress a different feel, and the base needs to provide the support specified by the mattress manufacturer. The NBF describes both rigid and flexible sprung slatted bases and advises consumers to ensure the base properly supports the mattress.
Before ordering, run through a final practical checklist:
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Confirm mattress and bed-base compatibility, including any requirements for slat spacing or base condition.
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Read the home-trial rules, particularly adjustment periods, collection charges and mattress-condition requirements.
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Read the warranty exclusions, rather than judging a warranty solely by its advertised length.
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Check delivery access and old-mattress removal costs before checkout.
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Look for clear UK safety and compliance information and buy from an identifiable, reputable retailer.
The trial period deserves particular attention when shopping online because a few minutes testing a mattress cannot reproduce several nights of normal sleep. When testing in a shop, the National Bed Federation recommends lying on a mattress in your normal position for at least 10 minutes rather than simply sitting on its edge.
Adeline Waterson currently advertises a 100-night mattress trial and recommends giving a new mattress around 30 nights to adjust before deciding whether it is right. Its returns policy currently states that a £30 collection charge applies to trial-period returns and that refund reductions may apply where a returned mattress is stained, torn, heavily soiled or otherwise damaged. Because commercial terms can change, buyers should check the live policy at the time of purchase.
The same principle applies to warranties. Adeline Waterson’s current warranty information states that eligible products include three years of manufacturing-defect cover, with eligible purchases able to receive extended cover to a total of 10 years under the applicable offer.
Finally, protect the mattress after buying it. Follow the manufacturer’s instructions on rotation and flipping because not every mattress is designed to be turned over. The NBF recommends rotating mattresses regularly, using a mattress protector and ensuring the underlying base remains supportive. Some initial body impressions can be normal as comfort fillings settle and conform to the sleeper.
For UK buyers, safety should also be part of the decision. Government guidance confirms that UK furniture fire-safety regulations impose flammability requirements on domestic upholstered furniture, while the National Bed Federation’s approval scheme independently audits member manufacturers for procedures covering issues including flammability, hygiene and trade descriptions.
The Best Mattress Is the One That Gets the Fundamentals Right
Buying a mattress becomes much easier when you stop looking for a universal “best mattress” and start looking for the right combination of space, support, pressure comfort, construction and buying protection.
Measure the bed first. Choose firmness according to how the mattress supports your body rather than assuming harder is better. Understand what the springs, foam and comfort layers actually do. Take your partner’s needs into account. Then check the less exciting details base compatibility, trial conditions, warranty terms, delivery and care instructions before placing the order.
Mattress design will continue to offer more materials, comfort layers and increasingly elaborate specifications, but those fundamentals are unlikely to change. A mattress is ultimately successful when its construction suits the people sleeping on it and continues doing so night after night.
Frequently Asked Questions
What firmness of mattress should I buy?
Choose according to your body weight, build, sleeping position and comfort preference rather than the firmness label alone. Firmness ratings are not standardised between mattress manufacturers.
Is a firm mattress always better for back pain?
No. The National Bed Federation advises that a hard mattress is not automatically better for somebody with a bad back. Appropriate support and personal comfort are more important.
Are pocket-sprung mattresses good for couples?
They can be. Because pocket springs respond independently, they can reduce roll-together and limit how much movement is transferred across the mattress compared with interconnected spring systems.
Should I replace my bed base when buying a new mattress?
Check it carefully. An old, damaged or incompatible base can affect how a new mattress feels and performs. The NBF advises ensuring that the base provides sufficient support for the mattress.
How do I know when my current mattress needs replacing?
Look at performance rather than age alone. Persistent discomfort, significant sagging or lumps, worn springs, excessive roll-together and a noticeable loss of support can all indicate that a mattress is no longer performing as it should.
