How To Choose The Right Degree Of Firmness - UK Guide (2022)

The firmness of a mattress describes - as the name suggests - how soft or firm a mattress feels.

This could be soft and fluffy like a cloud (or, at least, what we all imagine when we think about diving into a cloud) or as hard as a table 🌥

Differences in mattress firmness are caused by the use of different materials and their respective densities.

Unfortunately, there is no uniform industry standard for a mattress's firmness rating.

And this is where the confusion sets in.

Some brands use terms like H2, H3, and H4. Others simply describe their mattresses as 'softer' or 'firmer'. And others, again, refrain from specifying any degree of firmness and call their mattresses one-fits-all universal types of medium firmness.

How are we supposed to make sense of that? 🤔

Don't worry; we came up with a grand solution, which we dive into further below.

For now, it's important to remember that there are different types of mattresses.

Soft mattresses

These are generally memory foam mattresses with lots of body-contouring support, cushioning and extra padding.

They are popular with people looking for superior comfort and relaxation and give you that sleeping-on-a-cloud feeling.

You'll often find mattresses that have an upper comfort layer of memory foam to provide extra squishiness.

Medium-firm mattresses

These are the perfect in-between, mattresses that are not too soft and not too firm.

Medium-firm mattresses will suit most people.

We could describe these as your marshmallow mattresses: still soft and squishy, but with a lot more firmness than a cloud.

Firm mattresses

Firm mattresses generally offer high levels of support and durability.

They are well-suited to athletes and people struggling with back pain and tension.

These are your sleeping-on-a-table mattresses, but, of course, there are also various levels here and not all tables are hard as concrete.

Creating a firmness scale

There are many factors that can influence how firm a mattress feels and, as we've just discovered, you can't always rely on a brand to give you an exact degree of firmness.

This is why we've created the Sleep Hero firmness scale.

We've found this especially useful for bed-in-a-box mattresses 📦

As you'll be buying your mattress online, you can't rely on the general feel of a mattress as you would if you were buying from a traditional brick-and-mortar retailer.

We use our firmness scale in all our mattress reviews and buying guides to help you figure out which is the perfect mattress for you.

Choosing the right degree of firmness is important for healthy spinal alignment 📏

If your chosen mattress is too firm, then your body will be forced to remain unnaturally straight, resulting in a misalignment of the spinal column.

On the flip side, if your mattress is too soft, you'll sink into the mattress too deeply, resulting in a hollow back.

In both cases, your spine will be misaligned, which can lead to tension and lower back pain.

Your sleep will also be impacted and you'll be far less comfortable.

If you choose the right mattress with the right degree of firmness, though, your body will sink in at the centres of gravity (i.e. your shoulder and pelvis) but remain well-supported everywhere else.

This allows your spine to remain straight throughout the night, easing tension and allowing for a comfortable night's rest.

Choosing the right degree of firmness, then, is essential for a good night's sleep 😴

If you already struggle with severe back, neck, or joint pain, it's even more important to be aware of firmness levels and choose a mattress with the right level of support.

We'd strongly recommend choosing a mattress that meets orthopaedic requirements.

But what about stability?

Even though we refer to firmness as "the factor that determines how well you're supported", there is a deeper aspect that you need to pay attention to.

It's important to note the difference between firmness and stability.

People often assume that a firm mattress is necessary to keep your spine straight and that a soft mattress will automatically lead to back pain.

This isn't necessarily true.

A firm mattress can result in back pain if it's not the right fit for you.

Similarly, a soft mattress can have excellent stability and be perfect for you.

You always need to choose a mattress with good stability. All of the ones we recommend offer good stability and support.

Firmness can be a matter of personal preference.

But your build, weight, and height will impact which degree of firmness is best for you to ensure that the mattress you choose can support your body.

Even if you have a mattress that offers good overall support and stability, you still need to find a mattress with the right degree of firmness for you.

General sleeping preferences and your sleeping style may play a role, but the most important factors to consider include your weight, height, and preferred sleeping position 🤸‍♀️

You should consider the following general guidelines when choosing the right degree of firmness:

• The heavier or larger you are, the firmer your mattress should be.
• Side sleepers and lighter-weight people often require softer mattresses than back and stomach sleepers.
• Conversely, back and stomach sleepers require firmer mattresses.
• Your height also plays a role. If you are very tall, you may require a firmer mattress.

Degree of firmness according to bodyweight

Bodyweight is a decisive factor when selecting the right degree of firmness 🏋️‍♀️

But, since you also need to consider height, build, and prefered sleeping position, we can only give general guidelines and you still need to consider everything on a case-by-case basis.

The following table may help you decide which degree of firmness is right for you:

Degree of firmness according to sleeping position

Your sleeping position also greatly impacts which degree of firmness will be right for you.

Side sleepers

With side sleepers, only a few parts of the body touch the mattress.

This means that your entire body weight is focused at these points, putting an enormous amount of pressure on the mattress and creating distinct pressure points.

Side sleepers should choose slightly softer mattresses.

These allow your hips and shoulders to sink into the mattress much more deeply, keeping the spine in a healthy alignment.

Stomach and back sleepers

Front sleepers and back sleepers can afford to choose slightly firmer mattresses.

In both of these sleeping positions, sleepers need more support to keep their hips lifted and prevent the formation of a hollow back.

Couples should pay special attention to the degree of firmness before buying a mattress.

This is simply because not every degree of firmness will be equally suitable for both partners 👩‍❤️‍👨

In general, we'd recommend sticking to medium-firm mattresses and making use of risk-free trial periods to make sure both partners sleep comfortably.

If you and your partner are of largely varying heights or body weights, though, you may need to make a different plan.

Two single mattresses

One option would be to buy two single mattresses that are the same height but have different degrees of firmness.

In this way, each mattress will be perfect for each individual, ensuring that both partners can sleep well.

You can always buy a bed bridge to get rid of the little gap between the two mattresses.

Customisable mattresses

You could also invest in a customisable mattress.

These are mattresses that offer different degrees of firmness on each side of the mattress so that each half can be individually adjusted.

This is ideal but can be a little more expensive.

Firmness is also important to consider when buying a mattress for your child.

While children over the age of 6 can sleep quite comfortably on adult mattresses, babies, toddlers, and small children under 6 generally require a special cot mattress.

These offer the perfect medium-firm feel to support growth and healthy bone development.

If a child's mattress is too soft or too firm, there is a risk of spinal deformities developing - especially at an early age.

Teenagers can orient themselves according to more general firmness scales.

If you've already browsed through our mattress reviews, you'll undoubtedly have come across references to the Sleep Hero firmness scale.

We've decided to create our own firmness classification system as it allows us to more easily compare mattresses to each other.

Plus, considering how inconsistent conventional firmness designations are, we needed a scale that would make sense to you, our readers.

We rate mattresses on a scale of 1 to 10, where 1 is the softest and 10 the firmest.

Our firmness scale is based on our personal experiences and comparisons with different people in different sleeping positions.

Using our scale, we would recommend the following degrees of firmness to people with different sleeping positions:

We've reviewed dozens of mattresses but it can be nice to get an overview of where all of these fall in terms of firmness.

The below table will give you a quick overview of our firmness scale and where we've placed different mattresses that we've reviewed.

Unfortunately, this isn't really possible.

Some mattress brands offer their mattresses in different levels of firmness, so you can choose whether you want the mattress in soft, medium, or firm before you buy.

Other brands, like Emma, can provide an additional layer to add some softness or firmness to the mattress.

But, generally, it's near to impossible to change the level of firmness once you've bought a mattress.

There are still ways to fix the problem.

Risk-free trial periods

If the mattress you've just bought is too firm or too soft and you're still within the trial period, you can simply return your mattress - free of charge - and get a full refund.

But, unfortunately, if the trial period has expired, you'll have to consider buying a new mattress.

Mattress toppers

If your mattress is too firm, though, you're in luck as this can possibly be fixed by investing in a mattress topper.

Mattress toppers are great as they're generally intended to soften up a firm mattress.

Toppers can be made from a variety of materials, including memory foam, cold foam, or latex foam.

If your aim is to add a cushioning top layer to your mattress to increase its softness, we'd recommend opting for a memory foam mattress topper.

We've recommended a few of our favourite ones below.

Finding the right degree of firmness is essential, not only to the quality of your sleep but also to your health.

You need to find a mattress that will support you and keep your spine in an optimal alignment so you can wake up feeling refreshed and without any sort of tensions, aches, or lower back pain.

Our Sleep Hero firmness scale has been specifically designed to help you navigate the world of mattress firmness and find the mattress that's perfect for you.