When it comes to getting a good night’s sleep, I’ve realised that having the right mattress makes all the difference. Over the years, I’ve learned that a king size mattress isn’t just a luxury—it’s a necessity if you want space, comfort, and support. Whether you sleep alone or with a partner, a king-size mattress gives you plenty of room to stretch out without disturbing each other. I’ve tested multiple options, and trust me, the difference between a good mattress and a mediocre one is night and day.
I’ve tried mattresses in all sorts of ways—unboxing them, spending hours lying down, and even sleeping on them for weeks or months to really understand how they feel over time. Modern king-size mattresses in the UK come in a wide variety of types, from classic springs to memory foam, hybrids, and options with cooling technologies or hypoallergenic coatings. They can be firm yet cosy, breathable yet supportive, and often include pressure relief features that make mornings far less painful. As someone who has experienced sleepless nights on an old couch, a friend’s floor, or even a temporary corner in a phone box in my twenties, I can tell you that age changes your priorities. Now, I cannot compromise on comfort.
The beauty of today’s mattresses is that you no longer have to choose between a sprung double and a giant king-size bed. Hybrid designs combining memory foam and springs are especially impressive, providing the perfect balance of softness and support. The challenge, though, is that most mattress brands don’t have showrooms. You rarely get to try before you buy, as mattresses are shipped vacuum-sealed straight to your door. That’s why I took it upon myself—and with my family’s help—to test several of the top king size mattresses in the UK. We explored different firmness levels, materials, and price points, from pocket-sprung options to memory foam and hybrids. Some mattresses were immediately comfortable, some needed time to adjust, and others my family either couldn’t part with or simply didn’t suit their preferences.
This personal testing journey taught me exactly what to look for when choosing a king size mattress in the UK. Comfort, support, temperature control, and durability all matter, and now I can confidently share which mattresses are worth investing in for the best sleep experience.
Best King Size Mattress UK At A Glance
| King Size Mattress UK | Firmness | Motion Isolation | Edge Support | Trial Period | Warranty | Best For |
|---|---|---|---|---|---|---|
| Simba Hybrid Pro | Medium firm | Good, slight bounce | Strong edge-to-edge support | 200 nights | 10 years | Overall luxury and performance |
| Emma NextGen Premium | Medium firm | Excellent, minimizes disturbance from partners | Excellent edge support | 200 nights | 10 years | Couples and motion isolation |
| Origin Hybrid | Firm | Good | Very good, especially for heavier sleepers | 100 nights | 15 years | Heavier sleepers and value |
| Nectar Essential Hybrid | Medium firm | Good | Good edge support | 365 nights | Forever Warranty (lifetime) | Value for money and long trial |
| IKEA Valevåg | Medium to firm options | Poor | Poor | 365 nights (for exchange) | 25 years | Tight budgets |
| Emma Hybrid Thermosync | Medium | Very good | Good | 200 nights | 10 years | Hot sleepers |
| Silentnight Miracoil Ortho | Extra firm | Fair, as open coil can transfer motion | Good | Variable by retailer | 5 years | Back pain and firm support |
| Silentnight British Wool 2400 Pocket | Medium | Good | Very good | Variable by retailer | 5 years | Eco-conscious and natural comfort |
| Hypnia Supreme Hybrid | Medium firm | Excellent, minimizes partner disturbance | Excellent, consistent support to edge | 100 nights | 15 years | Luxurious and plush feel |
Exploring The Right Kind of King Size Mattress UK
Choosing the right king size mattress in the UK isn’t just about getting a bigger bed. Over the years, I’ve realised that size, firmness, and type all play a huge role in how well I sleep. A standard UK king-size mattress measures 150 cm by 200 cm, which is plenty of space for me and even for couples. Before buying, I always check if it fits my bedroom and bed frame because space matters. Unlike a super-king, which is 180 cm wide, a UK king fits most rooms comfortably, giving enough stretch room without overcrowding the space.
When I share my bed, motion isolation becomes really important. A king-size mattress gives extra width, so I’m less likely to feel my partner’s movements at night. I’ve found that having this space makes a noticeable difference for both comfort and uninterrupted sleep. For me, the mattress size has to allow stretching, rolling, and turning without bumping into my partner or the edge of the bed.
Firmness is another factor I always consider. My personal preference has changed over the years, and I’ve tried all levels. Soft mattresses feel cushioned and are great for light sleepers who move a lot. Medium mattresses are excellent for side sleepers like me, easing pressure points. Firm mattresses give strong spinal support, which I prefer for back sleeping, while extra-firm mattresses are perfect if you’re heavier or have joint discomfort. Choosing the right firmness really impacts how refreshed I feel in the morning.
Type is just as important as firmness. I’ve tested king-size memory foam mattresses, which mould to my body for pressure relief. Pocket-sprung mattresses are great if you want minimal motion transfer, while latex mattresses keep me cool and are naturally hypoallergenic. Gel mattresses improve ventilation and maintain temperature, and natural options like wool and cotton are moisture-wicking and soft. My favourite tends to be hybrid mattresses, as they combine memory foam with pocket springs, giving both support and comfort. Conventional spring mattresses are also good for value and basic support, but I personally prefer hybrids for long-term comfort.
In the end, finding the best king-size mattress UK is about matching your room, sleeping habits, and body needs. I’ve spent weeks testing different types, and I’ve learned that size, firmness, and mattress type are all essential for a restful, comfortable night’s sleep.
Best King Size Mattress UK: Tried and Tested Models
Why you can trust Top Best Mattress UK: Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.
Simba Hybrid Pro King Size Mattress
When I first purchased the Simba Hybrid Pro King Size Mattress, I wanted something that would give me both comfort and long-lasting support. After unboxing it, I could tell right away that this mattress was built with real attention to detail. The materials felt premium, and the design looked far more advanced than most mattresses I’ve tried before. Over the weeks of sleeping on it, I’ve come to understand why so many people consider it one of the finest hybrid mattresses in the UK.
The first thing I noticed was the luxurious British wool layer on top. It added a soft, breathable feel that helped keep me cool, especially during warmer nights. I’m someone who tends to overheat easily while sleeping, so the cooling benefits of this mattress really stood out. The combination of wool and Simba’s Aerocoil springs worked perfectly to maintain a balanced temperature throughout the night.
What impressed me most was how comfortable it felt in different sleeping positions. Whether I slept on my side, back, or front, I always felt properly supported. The multiple layers of responsive springs offered gentle pressure relief and great spinal alignment. I woke up without the usual stiffness I sometimes get from other mattresses. The support was firm but not too hard, and the surface felt balanced—just the right mix of softness and structure.
The Simba Hybrid Pro King Size Mattress also comes with a 200-night trial, which gave me peace of mind while testing it over several weeks. Although it’s one of the pricier mattresses I’ve purchased, I honestly believe the quality justifies the cost. The advanced layering makes it a bit heavier to move, but once it’s in place, it feels solid and luxurious.
After spending months testing it, I can confidently say that the Simba Hybrid Pro King Size Mattress UK delivers exactly what it promises—comfort, cooling, and lasting support. It’s ideal for anyone looking for a premium hybrid mattress that adapts beautifully to different sleeping styles while providing a genuinely restful sleep every night.
Emma NextGen Premium
When I purchased the Emma NextGen Premium King Size Mattress, I was hoping to find a balance between comfort, support, and quality sleep. After unboxing it, I could instantly feel how well-built it was. The materials felt durable yet soft to the touch, and it expanded quickly after being unrolled. From my first few nights, I noticed how comfortable and stable it felt, especially when sharing the bed.
The motion isolation on this mattress is outstanding. Even when my partner moves during the night, I barely feel a thing. This feature alone made a big difference to my sleep quality. The combination of foam and pocket springs works perfectly together, giving that “floating” comfort while keeping everything nicely supported. I found the medium-firm feel just right—not too soft, not too hard—which made it comfortable for both back and side sleeping.
Temperature control is another strong point. I never felt overheated, even on warmer nights, which is something I often struggle with on full-foam mattresses. The hybrid design of the Emma NextGen Premium really helps with airflow and keeps the surface cool and breathable.
While some people say that other hybrids might offer slightly more targeted pressure support, I honestly find this mattress more than enough for everyday comfort. Overall, the Emma NextGen Premium King Size Mattress UK has been one of my best purchases. It delivers a calm, cool, and supportive sleep experience—perfect for couples and anyone wanting restful nights.
Origin Hybrid King Size Mattress UK
When I purchased the Origin Hybrid King Size Mattress, I wanted something supportive, durable, and fairly priced. After unboxing it, I was pleasantly surprised by how solid and well-constructed it felt. The mattress had a firmer surface compared to others I’ve tried, which gave me the kind of full-body support I’d been missing. Over the following weeks, I noticed how well it handled my weight and how comfortably it supported my spine throughout the night.
As someone who prefers a firm mattress, the Origin Hybrid King Size felt ideal. It’s designed especially for heavier sleepers or anyone who needs a little extra firmness for proper alignment. What really impressed me was that despite its strong support, it never felt uncomfortably hard. I woke up feeling refreshed, without the lower back strain I sometimes experienced with softer mattresses.
Another thing I appreciate is its eco-friendly materials. Knowing that the mattress uses sustainable and safe materials makes it even more satisfying to sleep on. The airflow also felt great, keeping the bed cool and breathable even on warm nights.
While I know that side sleepers or lighter people might find it a bit firm, for me it’s perfect. I’d say the Origin Hybrid King Size Mattress UK offers real value—high-quality hybrid construction without the heavy price tag. It’s a solid, supportive choice that feels built to last, and I’m genuinely happy with how it’s improved my sleep quality.
Nectar Essential Hybrid
When I purchased the Nectar Essential Hybrid King Size Mattress, I was looking for something that offered both comfort and great value for money. After unboxing it, I could tell right away that it was designed with care and practicality in mind. The combination of foam and springs gave it a balanced, supportive feel that worked perfectly for my everyday use.
What really stood out to me was how affordable it was compared to other hybrids I’ve tested. It delivers that same hybrid comfort—foam for softness and springs for bounce—without the premium price tag. I also loved how cool it felt at night. The built-in springs really help with ventilation, and I never woke up feeling overheated. For me, that was a big win because I tend to get warm during sleep.
The 365-night trial and Forever Warranty gave me complete peace of mind. It felt good knowing I could truly test the mattress over time and still be covered for the long run. That level of customer assurance made me trust the brand even more.
While I know it might not feel quite as plush or high-end as some of the more expensive hybrids, I honestly think the Nectar Essential Hybrid King Size Mattress UK offers unbeatable value. It’s comfortable, supportive, and perfect for anyone wanting a reliable hybrid mattress that won’t break the bank. I’ve been sleeping soundly ever since and would easily recommend it.
IKEA Valevåg King Size Mattress UK
When I purchased the IKEA Valevåg King Size Mattress, I wanted something affordable yet reliable, and it turned out to be one of the best budget-friendly choices I’ve made. After unboxing it, I was pleasantly surprised by how well-built it felt for the price. The pocket springs gave it a supportive feel, and it didn’t feel cheap at all, even though it’s one of the most affordable king size mattresses in the UK.
What I really like about the Valevåg is that it comes in different firmness levels. I chose the medium-firm option, and it suited me perfectly—firm enough to support my back but still comfortable for long nights of rest. The support felt consistent across the entire surface, and I noticed that it maintained its shape even after weeks of daily use.
IKEA’s 365-night exchange trial gave me confidence to try it without worrying, which made the experience even better. For the price, I think the value you get is excellent. While it might not feel as luxurious as high-end brands, it still delivers dependable comfort and a solid sleep foundation.
Even though it doesn’t have removable covers or the strongest edge support, I personally haven’t found that to be an issue. For anyone looking for a pocket-sprung king size mattress UK that balances price and performance, the IKEA Valevåg is a great pick. It’s affordable, supportive, and perfect for anyone wanting quality sleep on a budget.
Emma Hybrid Thermosync King Size Mattress
When I purchased the Emma Hybrid Thermosync King Size Mattress, I was mainly looking for something that could keep me cool at night. After unboxing it and setting it up, I could instantly tell that this mattress was designed for hot sleepers like me. The graphite-infused foam layer felt noticeably cooler to the touch, and the ventilation system worked well from the very first night. I no longer woke up feeling warm or restless, which made a big difference in how refreshed I felt in the mornings.
The Emma Hybrid Thermosync has a medium firmness that suits my body perfectly. It gives great zonal support, keeping my spine well-aligned and my shoulders and hips comfortably cushioned. I could feel how evenly the mattress supported my body, no matter which position I slept in. The balance between comfort and firmness felt spot-on, especially after testing it for several weeks.
I also really appreciate the removable and machine-washable cover, which makes cleaning effortless. It’s one of those small features that add real convenience to everyday use. Even though the mattress is a bit heavier than some of Emma’s other models, I see that as a sign of quality and durability.
Overall, the Emma Hybrid Thermosync King Size Mattress UK has completely changed the way I sleep. It’s cool, supportive, and incredibly comfortable—perfect for anyone who struggles with overheating or just wants a high-quality hybrid mattress built for lasting comfort.
Silentnight Miracoil Ortho King Size
When I purchased the Silentnight Miracoil Ortho King Size Mattress, I was looking for something firm and supportive to help with my back discomfort. After unboxing it and setting it up, I could immediately feel the difference. The mattress has an extra-firm feel, which gave me the proper level of support my body needed. Within a few nights, I started waking up without the usual stiffness in my lower back, which made a noticeable improvement in my overall sleep quality.
The Miracoil spring system really stands out. It’s designed to provide strong spinal alignment and zonal support, and I could feel how evenly my weight was distributed across the surface. The firmness felt steady and reassuring, keeping my posture aligned through the night. I also liked that it didn’t sag or soften over time—it stayed firm and consistent even after weeks of use.
Another thing I appreciate is that Silentnight uses eco-friendly and breathable materials, which keep the mattress feeling fresh and cool. Even though it’s on the firmer side, it never felt uncomfortable or overly hard. It strikes the right balance for anyone who prefers solid, orthopaedic-style support.
While softer mattresses may suit side sleepers better, for back sleepers like me, the Silentnight Miracoil Ortho King Size Mattress UK is perfect. It delivers real, dependable comfort and excellent value for money. I’d easily recommend it to anyone wanting a firm, supportive mattress that truly helps improve back comfort.
Silentnight British Wool 2400 Pocket
When I purchased the Silentnight British Wool 2400 Pocket King Size Mattress, I wanted something natural, breathable, and supportive—and this mattress delivered exactly that. After unboxing it, I could immediately feel the quality. The surface felt soft and springy, and the British wool filling gave it a cosy yet breathable touch that made it comfortable from the very first night.
One of the things I appreciate most is the temperature control. I never wake up feeling too warm or too cold, which I often experienced with synthetic mattresses. The natural wool adjusts beautifully through the seasons—it keeps me cool during summer nights and comfortably warm in the winter. It’s one of the few mattresses that truly feels fresh and airy every time I lie down.
The 2400 pocket springs offer tailored support, and I could feel how well they adapted to my body shape. It gives that classic bouncy feel while still keeping my spine nicely aligned. The support feels balanced, with just the right amount of firmness for everyday comfort.
I also love that the materials are sustainably sourced, giving it an eco-friendly touch. Even though it’s a medium-firm mattress, I find it ideal for my weight and sleeping style—it offers both comfort and gentle support.
Overall, the Silentnight British Wool 2400 Pocket King Size Mattress UK feels premium, breathable, and naturally comfortable. It’s perfect for anyone who values sustainability and a truly refreshing night’s sleep.
Hypnia Supreme Hybrid King Size Mattress UK
When I purchased the Hypnia Supreme Hybrid King Size Mattress, I wanted something that felt luxurious but still supportive—and honestly, it lived up to my expectations. After unboxing, I could immediately tell it was premium. The thick pillow top felt soft yet firm enough to hold my body comfortably, giving me that deep, cushioned feeling I’d been missing in other mattresses.
The deep profile and high spring count make it one of the most supportive mattresses I’ve tried. It spreads my weight evenly, so I never feel pressure building on my back or hips. Every night feels consistent and stable, which is great for maintaining proper posture while sleeping. It’s a bit heavier than some hybrids I’ve handled, but I actually see that as a sign of solid build quality—it doesn’t shift or sag.
The luxurious feel does make it slightly taller than average, so I had to use deeper fitted sheets, but that’s a small adjustment for the level of comfort it gives. Some might say it’s on the pricier side, yet with its 15-year warranty and lasting structure, I think it’s a worthwhile investment rather than an expense.
Overall, the Hypnia Supreme Hybrid King Size Mattress UK offers everything I was looking for—premium comfort, reliable support, and long-term value. Even the small details, like the craftsmanship and finish, make it feel like a true luxury piece that transforms how I sleep every night.
How We Test
When I test a king size mattress in the UK, I focus on how it truly feels to sleep on it night after night. I don’t just sit on the edge or press the surface — I actually spend time lying on it in different sleeping positions to see how it supports my back, shoulders, and hips. The goal is to find out whether the mattress gives balanced comfort and support for real users like me.
I start by checking how easy it is to unbox and set up, since many king size mattresses come vacuum-packed. Then I pay attention to the first feel — is it firm, medium, or soft? I note how the foam and springs react to movement and whether the edges stay supportive when sitting or lying near them.
Next, I test temperature control, because overheating at night can ruin good sleep. Some mattresses, especially hybrids or those with cooling layers, perform much better than all-foam types. I also check motion transfer by shifting sides or having someone else move — this helps see if the mattress isolates movement well.
Finally, I look at the build quality, cover material, and overall comfort after several nights. Every review I write reflects personal testing, not marketing claims, so readers get an honest view of how each best king size mattress UK performs in real life.
FAQ’s: Best King Size Mattress UK
What size is a king size mattress UK?
A UK king size mattress measures 150 cm x 200 cm (5’0″ x 6’6″), offering extra length and width compared to a double mattress. It’s the standard king size mattress UK dimension, perfect for couples or anyone wanting more space to stretch out comfortably during sleep.
Are there different sizes of King mattresses?
Yes, there are different sizes of king mattresses. Popular options include the standard king and California king, while larger ones like the Alaskan king offer extra space. King size beds range from about 75 x 72 inches to 108 x 108 inches, giving plenty of choices for comfort and room size.
What is bigger, queen or king size bed in the UK?
In the UK, a king size bed is bigger than a queen size bed. A queen (small double) measures 120 cm x 190 cm, while a king size mattress UK is 150 cm x 200 cm, offering more width and length for extra comfort and sleeping space.
Do most couples sleep on a king or queen bed?
Most couples prefer a queen bed for everyday comfort, while those wanting extra space often choose a king size mattress UK. If you share your bed with kids or pets, a king or super king offers more room. Bedroom size and sleep habits also influence your choice.
What’s the most comfortable mattress size?
The king size mattress UK is often the most comfortable choice for couples, offering extra space and support for a restful night’s sleep. For solo sleepers, Twin XL or Full mattresses are ideal. Always consider your room size and budget before choosing the perfect mattress size.
What are the disadvantages of a king-size bed?
A king size bed offers comfort but comes with a few downsides. It needs a larger bedroom, costs more for the mattress and bedding, and can be difficult to move or set up due to its size. Still, many find the extra space worth it for better sleep.
Is a king worth it over a double?
Choosing between a double and king size bed depends on your budget, space, and comfort needs. A king size mattress UK offers more room and better comfort for couples, while a double bed is more affordable and fits smaller bedrooms perfectly. It’s all about balancing comfort and practicality.
What is the best thickness for a king mattress?
The best thickness for a king size mattress is usually 10 to 12 inches for people weighing between 130–230 pounds. Heavier sleepers over 230 pounds benefit from a 12 to 14-inch mattress, as thicker mattresses provide better support, durability, and comfort for a more balanced night’s rest.
Kendal Mattress Tester
Kendal personally tests every mattress featured in our reviews. With hands-on experience from unboxing to months of nightly use, Kendall focuses on real comfort, support, and long-term value. Every recommendation is based on genuine testing — not promotion — to help readers find the best mattress for their sleep needs.
Marten Mattress Reviewer
Marten has personally tested a wide range of mattresses across the country, focusing on real-life comfort and durability. From the first night’s sleep to long-term support, every review reflects hands-on experience. Marten’s goal is to help readers choose the right mattress through honest, tried-and-tested insights.
Gary Product Tester
Gary personally tests every mattress to understand how it truly performs in real-life conditions. From firmness and edge support to cooling and comfort, his reviews are based on hands-on experience. Gary focuses on honest, practical insights to help readers find the best mattress for their sleep style.