How to Choose a Mattress: A Complete UK Buying Guide
Mattress types, firmness, size, sleep position and budget - everything you need to make the right choice with confidence.
Start with your sleep position and body weight to find the right firmness, then choose a mattress type that suits how you sleep - hybrid is the most versatile option for most people - and match the size to your bed frame. A good mattress should support your spine, suit your budget, and come with a home trial so you can test it properly before committing.
The average person spends around a third of their life asleep. The mattress underneath you during that time directly affects the quality of your sleep, your spinal alignment, and how you feel when you wake up. A poor choice leads to restless nights, stiff joints, and a mattress replaced far sooner than it should be.
The good news: choosing a mattress is simpler than the market makes it look. Ignore the jargon. Focus on four things: mattress type, firmness, size, and sleep position. Get those right and everything else falls into place.
1 Understand the main mattress types
Hybrid mattresses
A hybrid mattress combines pocket springs with layers of foam, gel, or other comfort materials. The springs provide support and airflow; the foam layers add pressure relief and cushioning. This combination makes hybrids the most versatile option for most sleepers - they suit back sleepers, side sleepers, and couples who need a balance between support and comfort.
If you are not sure which type to choose, a hybrid is the safest starting point.
From the entry-level Pocket 1000 to the premium 5000 Lux Elite, the full range is available with a 200-night trial and 15-year guarantee.
Browse hybrid mattresses →Pocket sprung mattresses
Pocket sprung mattresses use individually wrapped springs that move independently, responding to your body shape rather than pushing back uniformly. The higher the spring count, the more precisely the mattress contours to you. They are particularly good for couples because each spring responds individually, reducing partner disturbance when you move.
Memory foam mattresses
Memory foam moulds to your body in response to heat and pressure, then slowly returns to its original shape. It offers excellent pressure relief, particularly around hips and shoulders, which makes it popular for side sleepers. The main drawback is heat retention - memory foam traps warmth, which can be an issue for those who sleep hot.
Open coil mattresses
Open coil mattresses use a single wire system of interconnected springs. They are the most affordable option and have their place, but the springs move together rather than independently, which means more partner disturbance and a less precise response to body weight. Best suited to occasional-use or guest beds.
Latex mattresses
Latex is a premium, naturally derived material with a responsive, bouncy feel. It is durable, naturally cooling, and resistant to dust mites - good for allergy sufferers. Latex mattresses tend to be at the higher end of the price range.
2 Choose the right firmness for your sleep position
Firmness is not about personal preference - it is primarily about spinal alignment. The goal is to keep your spine in a neutral position throughout the night.
| Sleep position | Recommended firmness | Why |
|---|---|---|
| Side sleeper | Soft to medium | Allows hips and shoulders to sink in slightly, keeping the spine level |
| Back sleeper | Medium to medium-firm | Supports the lower back without excessive pressure at the hips |
| Front sleeper | Firm | Prevents hips sinking, which puts the lower back under strain |
| Combination sleeper | Medium | Versatile enough to accommodate multiple positions through the night |
Body weight also plays a role. Lighter sleepers (under around 10 stone) often find firmer mattresses unyielding and prefer a softer feel. Heavier sleepers (over around 14 stone) typically need a firmer tension to avoid sinking too deeply into the comfort layers.
Couples with different preferences should consider a zip-and-link mattress - two singles zipped together, each with a different tension. Alternatively, a medium-firm hybrid is often versatile enough to suit both sleepers on its own.
The 4000 Ortho Elite is designed for back and front sleepers who need a firmer, orthopaedic-grade tension. The 5000 Lux Elite offers a medium-firm feel with a cooling gel layer, suited to back and side sleepers who sleep warm.
3 Choose the right size
Match the mattress to your bed frame first. If you are buying both together, use this as a general guide:
| Size | Dimensions | Best for |
|---|---|---|
| Single | 90 × 190 cm | One adult or a child; smaller bedrooms |
| Small double | 120 × 190 cm | One adult wanting extra width; tight for two regularly |
| Double | 135 × 190 cm | Standard couple’s size; comfortable for most pairs |
| King size | 150 × 200 cm | Extra width and length; better for taller sleepers or couples needing more space |
| Super king | 180 × 200 cm | Maximum space for two; requires a larger bedroom |
A useful rule of thumb: the mattress should be at least 10 cm longer than the tallest sleeper. Taller adults (over 6 ft) should consider king size or super king as a minimum.
4 Think about temperature
Hot sleepers should actively look for cooling features. Memory foam in particular traps body heat, which can disrupt sleep during the night. Look for:
- Gel-infused foam layers - gel regulates temperature by drawing heat away from the body
- Pocket spring systems - springs allow air to circulate through the mattress core
- Breathable cover fabrics - Tencel and bamboo-derived fabrics are naturally moisture-wicking
The 5000 Lux Elite features a cooling open-cell memory comfort layer alongside a high-count pocket spring system for airflow throughout the mattress.
5 Consider your back health
A mattress does not cure back pain, but the wrong one can make it worse. As a general principle:
- Lower back pain tends to respond well to a medium-firm hybrid, which provides enough give to relieve pressure points without allowing the hips to sink into misalignment
- Shoulder or hip pain (often side-sleeper related) responds better to a softer comfort layer that cushions those pressure points
- Orthopaedic needs are generally best served by a firmer mattress that maintains a consistently level surface
If back health is a primary concern, a long home trial is particularly valuable. Your back’s response to a new mattress can take several weeks to stabilise, and a short in-store test will not tell you much. Look for a trial of at least 100 nights.
The 4000 Ortho Elite is designed specifically for those seeking firmer orthopaedic-grade support.
6 Set a realistic budget
In the UK, most people spend between £400 and £1,200 on a double mattress. As a rough guide:
- Under £400: functional for occasional use; shorter lifespan
- £400-£800: solid mid-range; most hybrid and pocket sprung options sit here
- £800-£1,500: premium comfort layers, higher spring counts, longer guarantees
- Over £1,500: luxury materials (latex, natural fillings); diminishing returns for most sleepers
A mattress gets used every single night. Divided over a seven-to-ten-year lifespan, even a £1,000 mattress works out to pennies per night - it is worth spending more here than most people initially expect.
What to look for when buying online
Most mattresses sold in the UK are now bought online without an in-store test. The key protections to look for:
- A home trial of at least 100 nights - your body needs time to adjust to a new mattress, and a short window is not enough to make a fair judgement
- A guarantee of at least 10 years - the minimum marker of a manufacturer standing behind their product
- Free returns - a home trial means nothing without a risk-free return; check the small print
Every REM-Fit mattress comes with a 200-night home trial and a 15-year guarantee. If it is not right, we collect it free of charge and refund you in full.
Read the full trial terms →Frequently asked questions
How often should you replace a mattress?
Most mattresses last between seven and ten years, though this varies by type and usage. Signs it is time to replace: visible sagging, waking with stiffness or pain that was not there before, or noticeably better sleep in a hotel bed.
Is a firmer mattress better for your back?
Not necessarily. The right firmness depends on your sleep position and body weight. A mattress that is too firm can create pressure points; one that is too soft allows the spine to fall out of alignment. Medium-firm is the most commonly recommended starting point, but individual needs vary.
Can two people share a mattress with different firmness preferences?
Yes, via a zip-and-link setup - two mattresses with different tensions zipped together. Alternatively, a medium-firm hybrid is often versatile enough to suit a range of preferences on its own.
What is the difference between a hybrid and a pocket sprung mattress?
A pocket sprung mattress uses springs only. A hybrid combines pocket springs with comfort layers (foam, gel, or similar) on top. The hybrid typically offers more pressure relief and suits a wider range of sleep positions.
Do I need a mattress protector?
Yes. A protector extends the life of your mattress, protects the warranty (most manufacturers require one), and is far easier to wash than the mattress itself. Waterproof options are particularly useful in households with children or pets. Browse the REM-Fit mattress protector range.
When is the best time to buy a mattress?
Black Friday (late November) is the single best time to buy, when most brands discount their full ranges. Bank holiday weekends also typically carry promotional pricing. If you cannot wait, most brands run rolling sales throughout the year - check our current offers for the latest deals.
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