How we test products
Our mission is to take the guesswork out of finding the perfect sleep products.
We've dedicated hundreds of hours to testing mattresses and sleep accessories, and rely on a team of testers of differing weights, temperature preferences, and sleeping positions to evaluate each product.
Tested products are granted the Sleep Hero tested stamp of approval, a mark of our review's reliability.
If we haven't personally tested a product, please be assured that we invest significant time and energy into scouring the UK market and researching the best recommendations, and we work with a team of sleep experts who review our articles, ensuring that the insights we provide are not only relatable but also reliable.
What is a memory foam mattress?
Memory foam may sound like a new-age phenomenon, but it's actually been around for quite a few decades.
NASA first designed it as a pressure-absorbing material to cushion astronauts' seats and absorb impact during space travel. 🚀
And how did this space-age material end up in mattresses?
Well, you have Tempur to thank for that, who started playing around with memory foam in mattresses back in 1991.
Tempur memory foam mattresses are still some of the best in the world, though a bit on the expensive side.
We can recommend much more affordable ones!
Today, memory foam mattresses are very popular - especially in the form of bed-in-a-box mattresses.
We'll tell you why a little further down. 😉
What is memory foam?
In a nutshell, memory foam (also often called viscoelastic polyurethane foam or low-resilience polyurethane foam) is a foam made predominantly of polyurethane and a few additional chemicals to increase viscosity and density.
Memory foam is characterised by its so-called memory effect or memory imprint.
When you apply pressure to the foam, it leaves an imprint that will remain visible for a few seconds.
Look at the images below that demonstrate this memory effect.👇
This memory effect allows the memory foam to adapt remarkably well to the body, resulting in body-hugging comfort and support.
Memory foam also responds to temperature.
The foam will be firmer when cold and soften up when warmer.
As you warm up while sleeping, the foam will become softer and mould to your body even more.
This is great if you're looking for that body-contouring support.
But, in poorer quality mattresses, this can quickly become problematic.
As poorer quality memory foam mattresses respond slower, they may take a while to react to your body and bounce back to the original shape.
This can result in bad sleeping positions, leading to aches and pains.
Are memory foam mattresses 100% memory foam?
Most memory foam mattresses actually don't consist of 100% memory foam.
They're usually constructed of multiple layers of different types of foam to offer both comfort and support.
Memory foam on its own can be a little soft.
You'll often find memory foam mattresses constructed of an upper layer of viscoelastic foam and a lower layer of cold foam.
Cold foam provides additional support and stability. 💎
Many spring mattresses also have a memory foam pillow top for extra comfort.
The Hypnia Supreme Hybrid is one of our favourite pillow top mattresses.
Bed-in-a-box memory foam mattresses
Many of the mattresses we recommend are bed-in-a-box mattresses.
These are predominantly made of memory foam.
Memory foam can be compressed quite significantly, so a memory foam mattress can be squashed together, rolled up, and sent to you via post in a compact box. 📦
That's a pretty unique feature.
Once you unpack the mattress and remove the vacuum seal, it'll slowly return to its full size.
All the mattresses we recommend in this article, like the Ergoflex, are of the bed-in-a-box variety.
Criteria to consider when purchasing a memory foam mattress
We wish we could tell you that all memory foam mattresses are created equal, but, unfortunately, that's not the case.
As with all purchases, you need to ensure that you're investing in a quality product guaranteed to last you for a long time.
You also need to find one that is perfectly matched to suit your individual preferences.
Luckily, you have us to guide you. 😀
Below, you'll find a list of criteria to consider when purchasing a memory foam mattress.
1. High density
The most important quality feature of a memory foam mattress is its density.
Density is measured in units indicating how much polyurethane foam was used for one cubic metre.
The rule of thumb is this:
The higher the density, the higher the quality of the mattress. 👍
A higher density mattress is also less likely to suffer from dents and sagging, resulting in an overall longer lifespan.
A good memory foam mattress should last for 8 - 10 years.
You can use the below table as a rough guideline to density and lifespan:
|Density in kg/m³||Quality indicator||Expected lifespan|
|Under 30||Inferior quality||Up to 3 years|
|30-40||Average quality||3 - 6 years|
|40-50||Good quality||6 - 8 years|
|50-60||Very good quality||8 - 10 years|
|Over 60||Excellent quality||10 years and more|
2. What other materials are used?
Most memory foam mattresses consist of a memory foam layer combined with several layers of other types of foam.
The upper comfort layer is usually your viscoelastic memory foam while the lower support layers are often made from cold foam.
This gives the mattress more stability.
But you're also likely to find a range of other materials in your mattress, ranging from gel foam to aloe, bamboo, or wool. 🌱
These may affect the comfort, breathability, and support features of your mattress.
The Simba Hybrid Luxe, for example, features a top bamboo wool layer to enhance temperature regulation.
It's important to pay attention to the quality of these other mattress materials as well.
3. Pay attention to the degree of firmness
Memory foam mattresses are generally on the softer end of the scale.
The foam also reacts to temperature and is likely to become even softer as it warms up while you sleep. 💤
But, the actual degree of firmness of your mattress depends significantly on the other mattress materials used.
You can even find some firm memory foam mattresses, like the Nectar.
Unlike many other memory foam mattresses, the Nectar has a firmer top layer to counteract the softer memory foam - hence its firmer and more supportive feel.
There is no right or wrong when choosing a degree of firmness, though your sleeping position and build/body weight will influence this a bit.
Ultimately, you need to choose a mattress that allows your spine to remain optimally aligned.
If you sleep on your side, for example, you're likely to need a slightly softer mattress to allow the heavier parts of your body to sink in.
This will allow for optimal spinal alignment.
Take a look at the illustration below.👇
As you can see, the hips and shoulders sink in a little more deeply while the lighter parts of the body are adequately supported.
This allows your spine to remain straight, eliminating causes of tension and resultant back pain.
If you're a back or stomach sleeper (or if you're of a slightly larger build), you'll need a mattress that's a little firmer to provide enough stability and support.
Determining the right degree of firmness can be challenging. 🤯
This is why we've devised the Sleep Hero firmness scale.
Here, we rate mattresses on a scale of 1 to 10, where 1 is the softest and 10 the firmest.
All of the mattresses we review receive a value on this scale to help guide your purchasing decision. 🛍
But, ultimately, you will need to sleep on a mattress for a few weeks to see if the firmness is right for you.
That's why we always recommend choosing a mattress that comes with a risk-free trial period.
4. Risk-free trial periods
We can certainly help guide you in finding the best mattress.
That's what Sleep Hero is all about. ⭐️
But the only way to really see if a mattress is right for you is to try it out yourself.
We're not talking about lying on a mattress for a few minutes in a retail store.
Everything feels comfortable for a few minutes. 🤷♀️
To really see if a mattress is right for you, you need to sleep on it for a period of at least three weeks.
This gives your body the chance to get used to a new feel, which is especially important if your new mattress is vastly different from your old one.
We always recommend purchasing a mattress that comes with free delivery, a risk-free trial period, free returns, and full refunds.
These make your mattress purchase a risk-free investment.
Trial periods differ by brand, but most offer a minimum of 100 days. 🗓
Our favourite memory foam mattresses offer the following:
- The Ergoflex comes with a 30-night trial.
- The Nectar mattress comes with an industry-leading 365-night trial!
If you've slept on one of these mattresses for a few weeks and still don't find it as comfortable as you had hoped, you can send it back and receive a full refund. 💰
That's the kind of service we enjoy.
What do memory foam mattresses cost?
You may be able to find some cheap memory foam mattresses in the UK, but these are usually quite thin and won't last you very long.
We wouldn't recommend these.
Dormeo also has some budget options that might be suitable, but they won't be as good quality as their Octaspring collection.
We also wouldn't recommend IKEA memory foam mattresses. Some of the more premium ones are okay, but there are many better products available.
Most high-quality memory foam mattresses will set you back between £400 and £550 for the smallest size.
Of course, you can pay significantly more for a Tempur memory foam mattress or a little less for a budget Silentnight or Sealy mattress.
But most of our recommended mattresses are in that price range.
The best memory foam mattress deals
This doesn't mean you can't get a great deal on your new memory foam mattress.
Most of the UK bed-in-a-box brands we recommend, like Simba, Eve, or Nectar, regularly offer discounts and promotions.
A good coupon code can get you up to 45% off. 🥳
You don't have to spend hours searching the internet for a good deal.
We collect all of the best coupon codes for you and display them on our discounts page.
Simply select your code, apply it upon checkout, and enjoy your savings.
Memory foam mattress toppers
A mattress topper is a relatively thin layer of extra padding that can enhance the comfort of your mattress.
They are predominantly used to add some softness to mattresses that may otherwise be too firm.
Many mattress toppers are made from memory foam.
This is because memory foam is so soft and comfortable, making it the perfect material to add a little soft cushioning to the top of your mattress. 🤗
So if you've purchased a hybrid or pocket sprung mattress and you generally like the feel of it but want a touch more comfort, a memory foam mattress topper is the perfect solution.
Memory foam toppers are also available in all standard UK mattress sizes, including the popular memory foam mattress topper small double and memory foam mattress topper king size.
Our favourite UK memory foam mattress toppers:
Alternatives to memory foam mattresses
Memory foam is great - but it may not be the right choice for you.
If you're looking for a mattress that's perhaps more breathable or less body-hugging, then consider the below alternatives.
Spring mattresses are often firmer and offer more stability than memory foam mattresses.
They usually feature a spring core with upper comfort layers of foam.
Springs allow for greater elasticity and enhanced breathability, making them the perfect choice for people who need more support and enjoy a cooler sleep. ❄️
Quality is important when it comes to spring mattresses.
Many inferior spring mattresses, like open coil mattresses, can create or worsen back pain.
We always recommend pocket sprung mattresses.
Cold foam mattresses
Cold foam mattresses demonstrate high adaptability and are often used for orthopaedic purposes.
They're easier to move around on, too, so they're better suited for restless sleepers.🕺
Most mattresses feature a base layer of cold foam for enhanced stability and support.
Gel foam mattresses
Gel foam mattresses are very comfortable, providing a soft and cuddly feel.
They also allow for enhanced airflow, which keeps you cooler. 💨
Gel foam is most commonly found as an upper comfort layer in a combination foam mattress, used together with more adaptable and/or stable and firmer base foams.
Latex mattresses offer a very high degree of comfort.
High-quality natural latex mattresses also offer excellent ventilation, and they're a great organic mattress choice. 🐼
Unfortunately, pure latex mattresses are costly.
Hybrid mattresses usually combine high-quality memory foam with a core of pocket springs.
This results in a mattress that offers the exceptional adaptability and comfort of memory foam with the increased support, stability, and breathability of springs.