I imagine by the time you’ve reached this guide to memory foam mattresses you’ve already looked at several dozen mattresses, each with a more baffling description than the last.
You’ve looked at cross sections of foam and polysomething and you’re trying to work out what ‘density’ you need.
Take a deep breath, I’ve been there fellow shopper. Here’s our guide to buying a good quality memory foam mattress, and I promise not to use loads of ridiculous words that will make you feel you are back in high school double science lessons…
1. (Some of) the best memory foam mattresses have won awards and rave reviews
One way to speed up the memory foam mattress buying process is to pick one with great consumer reviews or industry awards.
Here are seven highly rated memory foam mattresses:
The Emma NextGen Cooling Mattress (£739) uses layers of foam on top and springs on the bottom. You could argue that makes it a ‘hybrid’ mattress rather a ‘memory foam’ mattress but it does have a layer of memory foam so I hope you’ll let me off.
It is the successor to the Emma Mattress/Emma Original Mattress, which was 100% foam. You also get a 10 year warranty.
Emma has won several awards and this model is considered medium firmness, so slightly softer than the Nectar Sleep and Ergoflex 5G. The brand scores 3/5 on TrustPilot, so some way behind Ergoflex and Nectar Sleep (featured later).
The Nectar Sleep Mattress (£600) is a medium/firm mattress that has won several awards. It scores 4.4/5 from customers on TrustPilot after thousands of reviews. The Nectar Sleep stands out thanks to its 365 night trial period and its ‘forever guarantee’ (with some Ts and Cs of course), which was unheard of when it first appeared on the market. You get a 3cm layer of memory foam on top of other foams, with the idea being that they all work together to give you the right support.
The Ergoflex 5G (£483) has a 30 night trial period, which is not as long as others. However, the mattress has been on the market in the UK for much longer and it gets a spectacular score of 4.8/5 on TrustPilot. It comes with a 10 year warranty, which is quite standard for a memory foam mattress of this price. Much like the Nectar Sleep it is rated as a medium/firm mattress.
The Ergoflex 5G stands out because it was one of the first mattresses to start offering the ‘bed in a box’ model, where you buy online rather than trying a mattress in a shop. Rivals such as Simba, Emma, Nectar and Eve came along and offered their own version of ‘the perfect mattress’. These brands have gradually increased their ranges over the last few years by adding ‘hybrid’ versions that use springs and other bells and whistles. Ergoflex has avoided going down that path and still just makes one mattress, which it considers to be ‘perfect’ for lots of its customers.
The Silentnight 3 Zone Memory Foam (£202) is a budget priced mattress from the biggest name in the UK mattress market. The most notable cost cutting has been made by making this mattress thinner than most others. However, it remains a popular option and the shallower than average depth might actually be a good thing if you are looking for a mattress for a trundle with a limited space. It is rated as a soft/medium mattress.
Most bunk beds only have space for a shallow mattress on top, because of the risk that you might fall out if the mattress is too high. A thinner mattress like this can be just what you need.
The Dormeo Memory Plus (£289) was awarded a Best Buy award by Which? magazine. Dormeo is an Italian brand that sells some innovative and expensive memory foam mattresses. However, they also sell this budget-friendly model which is considered medium firmness, so similar to the Emma mattresses.
The Tempur Pro Smartcool (£1499+) is made by the original memory foam mattress company, which took inspiration from materials used by NASA to develop its mattresses. The model shown below is medium-firm but you can choose from a range of firmness levels including soft, firm and extra firm.
The standard mattress by Tempur is called the Tempur Pro Smartcool but you can go for fancier versions that have more layers. The middle mattress in the range adds in the word ‘plus’ to become the Tempur Pro Plus Smartcool. If you really want to push the boat out, go for the Tempur Pro Luxe Smartcool, which is the deepest and most expensive in the range.
You can also buy Tempur adjustable bases that will massage you before you go to sleep. Read our full Tempur guide for more details on the ins and out of the Tempur range.
2. (Most of) the best memory foam mattresses are thick
An indicator of the quality of a memory foam mattress is its thickness. Cheap memory foam mattresses are about 15cm deep, whilst top quality and highest priced mattresses go up to about 30cm.
As you might have guessed, the general rule is that you’ll pay more for a thicker mattress.
For example, these three mattresses feature in our guide to Silentnight mattresses:
- The Silentnight 3 Zone Memory Foam mattress gets good reviews, but it is only 18cm deep, hence the £202 price tag.
- The Silentnight 7 Zone Memory Foam mattress is 20cm thick and costs about £100 more.
- The Silentnight Just Snug Memory Foam mattress is 25cm deep and costs about £500.
We can back up this theory with some data. We looked at the price and depth of mattresses in our guide to the best memory foam mattresses and came up with this graph:
For anyone currently figuring out what the graph shows, let me give a bit of analysis.
Broadly speaking, there is a correlation between the cost and depth of the memory foam mattresses in our comparison. The data is affected quite significantly by the Tempur mattress which costs three or four times as much as the rest but obviously isn’t triple the depth. Without that inclusion it would be a much clearer correlation. Even so, we can see a pattern.
Bear in mind that thick memory foam mattresses are very heavy. The super king size version of the Tempur Pro Luxe Smartcool Mattress weighs about 68kg (almost 11 stone) and needs rotating regularly. There would be a certain irony in getting a bad back from turning your £2000+ mattress…
Getting the firmness right
On a sort-of related note, make sure that you buy a memory foam mattress which is the right firmness for you. As a general rule, heavier people will need a slightly firmer mattress than lighter people and will get more benefit from a deeper mattress. Also, people who sleep on their side tend to go for slightly softer mattresses because their shoulders and hips sink into the mattress more than someone who sleeps on their back.
Rather frustratingly, there’s no industry agreed standard for mattress firmness but if you combine those two things together then you can have a guess of whether you need a soft, medium or firm memory foam mattress. For example, a heavier person who sleeps on their back will certainly want a firmer mattress than a lighter person who sleeps on their side.
3. The thickness of the ‘top layer’ of a memory foam mattress is important
There’s an old trick in catering where you bring out the best wine at the start. Once everyone is tipsy, you swap it for cheap wine and no-one notices.
Mattresses are a bit like that – the best quality and most expensive materials go on the top, and then cheaper materials are used underneath to pad it out. With a memory foam mattress, it’s worth looking at how thick the top layer of memory foam is.
For example, the Bodyshape Memory Foam mattress (£217) has a 3cm layer of memory foam whilst the Ergoflex 5G (£483) has a whopping 9cm layer of memory foam. I’m not saying that the Bodyshape mattress isn’t good value (it has very good reviews and it offers a lot for the price) but the Ergoflex uses considerably more memory foam.
My opinion is that you don’t necessarily need to have a massive layer of memory foam for a mattress to be comfortable and supportive, but if you’re paying a lot for a mattress with only a tiny layer of memory foam then you probably aren’t getting a good deal.
It gets a bit more complicated when you consider brands such as Tempur.
Whilst a lot of people think of Tempur as being the leading memory foam brand – and we include in some of our memory foam guides – the company understandably tries to differentiate itself from other brands.
Previously, Tempur has gone as far saying that ‘It is our opinion that standard memory foam mattresses are not very effective when it comes to relieving pain and pressure’. They now say that whilst their mattresses are ‘the original memory foam’ it is also the case that ‘no other memory foam is Tempur Material’.
A comparison might be with Heinz ketchup or with Coca Cola. You can buy cheaper tomato ketchup or cola, but if it doesn’t say the brand on the label then it isn’t the same.
This does make it rather difficult to compare like for like. Let’s look at a description of the Tempur Pro Luxe Smartcool, which says that it is made from:
- 5cm TEMPUR Advanced Material
- 10cm TEMPUR Adapt Material
- 3cm TEMPUR Dynamic Support Material
- 6cm TEMPUR Durabase technology
It isn’t entirely clear which of these layers could be considered memory foam. Does the mattress have a 5cm layer of memory foam layer or a 15cm layer?
What’s the cover story?
Another related thing to consider is that the best mattresses have a breathable cover. They might be made from something naturally breathable like cotton or a ‘breathable’ manmade material.
If it’s made from bog-standard polyester without any mention of breathability then it’s not so good, and it might add to the problem of some memory foam mattresses feeling too hot.
There are also lots of impressive sounding names for the outer material on a mattress (hypoallergenic, organic etc…). I haven’t yet found anything independently written which says that any of these hold magical powers, but just make sure it is something breathable.
4. The best mattresses have a decent warranty (and some have a trial period)
A long warranty is no guarantee of quality, but there’s a correlation between the price of a mattress and how long the warranty lasts for. To use the same example as before, the Silentnight 3 Zone Memory Foam Mattress (£202) comes with a 3 year warranty whilst the pricier Silentnight Just Snug Memory Foam mattress (£500ish) comes with a 10 year warranty.
In recent years, memory foam brands have been trying to out-do each other by offering even longer warranties.
Several memory foam mattresses now come with a 10 year guarantee such as Ergoflex 5G (£483) and mattresses from Eve Sleep and Emma.
Meanwhile, the Nectar Sleep Mattress has gone even further by offering a ‘forever’ warranty. I’m pretty sure no-one is going to able to beat that.
Obviously, there is small print to read with these things, as there is some variation in what is covered.
The trials of buying a mattress
Another thing to consider when buying a memory foam mattress is whether or not it comes with a risk free trial period.
Again, this is no guarantee of quality but it certainly makes it more appealing to the buyer. Instead of spending a few awkward seconds lying down in a showroom, you can try out a mattress for weeks or even months before deciding if you want to keep it. If you send it back, they are usually given away to a charity or recycled.
Most home trial periods allow you to get a refund if you don’t like the mattress whilst a few will only offer a swap for a different mattress. Sometimes there are hoops to jump through, such as always using a mattress protector so have a read of the terms and conditions before you buy it.
At the time of writing, some options include:
- a 365 night trial with the Nectar Sleep Mattress (£600)
- a 200 night trial with any of Emma’s mattresses
- a 200 night trial with the Simba Sleep Hybrid Original Mattress (£819)
- a 30 night trial with the Ergoflex 5G (£483)
For more ideas, see our guide to mattresses with a free trial. That guide includes advice on which sellers will offer you a refund and which will only offer an exchange if you don’t like the mattress.
5. (Most of) the best memory foam mattresses are ‘dense’
Feel free to nod off for this bit, it gets a bit technical.
Some memory foam mattresses come with a ‘density’ rating. It will probably be somewhere between 35kg/m3 to 85kg/m3. If the numbers don’t look like that, then you’ll need to get the calculator out to do some conversions of imperial to metric (or just give up and watch some telly).
It’s a bit complicated, but the main thing you need to know is that higher numbers are generally better, but it gets to a point where you don’t gain much from it being really dense.
From the many guides I’ve read, most people say that 50kg/m3 – 60kg/m3 is absolutely fine. A very low score suggests it is cheap.
Honestly though, I wouldn’t get too obsessed about density ratings because a lot of mattresses don’t actually give the rating as part of their specification.
You might also see a ‘firmness’ rating or an ‘ILD’ rating on a memory foam mattress. If you’re interested, it stands for Indentation Load Deflection, but my guess is that you don’t care…
These ratings don’t indicate quality, but they tell you what they will feel like to lie on.
One final thing…
There seems to be two schools of thought when it comes to memory foam mattress design. This may be a whole new level of boring for you, but let’s plow on regardless.
Some of the ‘bed in a box’ mattresses such as mattresses by Emma use memory foam in the middle of the mattress, like a slice of delicious visco-elastic ham in a sandwich. As a result, they don’t have such a significant ‘sinking feeling’ that you get with some memory foam mattresses. Some things I’ve read reckon this design means that you are less likely to feel too hot.
Meanwhile, some of the other ‘bed in a box’ mattresses such as the Nectar Sleep Mattress and the Ergoflex 5G use memory foam as the top layer, but also use clever techniques which they say will keep you cool. For example, the Nectar Sleep has a ‘cooling cover’ and ‘smart memory foam’ which ‘regulates your body temperature’ whilst the Ergoflex 5G has a ‘Cool Sleep Airflow System’ which ‘allows for air-flow and temperature regulation’.
For us shoppers, it’s worth realising that all of those brands mentioned have won awards from experts. Ergoflex and Nectar Sleep currently score higher than Emma Sleep on TrustPilot (see the full run down in our beginners’ guide).
As mentioned earlier, all of those ‘bed in a box’ foam mattresses mentioned above (and several others) are sold online and offer an appealing free trial ranging from one month to one year, so you can send it back if you’re not happy (check the small print, obviously).
A small number of other memory foam mattresses which you can try out in a shop offer something similar (Tempur do a 100 night trial and cost about £2000ish).