Your Sleep Matters!

How Do I Choose The Right Mattress Size?

How Do I Choose The Right Mattress Size?


Last updated: 04.08.2022 7.5 Min.

Even if buying a mattress can be a real headache, choosing its composition, size, and firmness are necessary steps.

After all, humans spend a third of their life sleeping!

That's a lot of time spent in bed, so you want to make sure it's not only the most comfortable bed ever but that it's also big enough to meet all your requirements - regardless of whether you need space for your laptop and some popcorn or a giant puppy 🐶

What is the perfect mattress size?

This can be a tough question to answer, but we've got you covered.

Check out our full Irish mattress size guide below 👇

Mattress Size

How to choose the right mattress size

You may have a vague idea about the size of mattress you need.

But actually deciding while you're hunting for a mattress can be a little more complicated.

There is no right mattress size.

Indeed, the right mattress size for you depends on a variety of factors, including your height and body weight, the size of your bedroom or studio apartment, and your family setup.

The below questions can guide you:

  • Are you short, tall, or of average height?
  • Are you light-weight, of average weight, or slightly heavier?
  • Do you sleep alone or do you share your bed with a partner?
  • Do you have children or pets that share your bed with you?
  • Are you a restless sleeper?
  • If you have a partner, is your partner a restless sleeper?
  • How big is your bedroom?

These questions may not give you a definitive answer, but they will help put you on the right path ✅

You can also consider the following:

  • If you're buying a replacement mattress, measure your current bed frame and bedding dimensions, and buy a mattress in the same size.
  • If you're buying a bed & mattress for the first time or you want to upgrade your bedroom setup, consider your budget (also include costs of the bed frame and bedding) and choose from there.

These factors can act as a guideline to help you choose your new bed.

Standard mattress sizes in Ireland

There are dozens of different mattress sizes available, including standard sizes and custom sizes.

Not only that, but each country will also have different standard sizes.

In Ireland, for example, the standard sizes are different to those available in mainland Europe.

This means that the dimensions of a double bed, for example, will be different in Ireland than in Germany.

Some mattress brands available in Ireland may offer European mattress sizes, which is great if you're moving countries and happen to have a ton of bedding in those sizes, but this is the exception and not the norm.

Below, we'll take you through the most common Ireland mattress sizes and give some guidelines on who they're the most suitable for.

We've included the standard size terminology, metric dimensions in centimetres, and imperial dimensions in feet and inches to make the size guide easier to navigate.

Mattress Sizes

Mattresses for children (various sizes)

There are a variety of standard mattress sizes that will suit children.

For babies and small children under the age of 6, the most common sizes include:

  • 60 x 120 cm
  • 70 x 140 cm

Most cot or baby mattresses are available in both of these sizes 👶

There is no right or wrong choice here, but you can consider the size of your crib, how big your baby is, and the size of your child's bedroom when making a choice.

For children or young teenagers, the most common size includes:

  • Small single mattresses sized 75 x 190 cm (2'6" x 6'3")

While children can also easily sleep on standard single mattresses or even larger, the small single bed is perfect for smaller bedrooms and smaller budgets.

Single mattresses sized 90 x 190 cm (3’ x 6’3”)

The standard single mattress in Ireland has dimensions of 90 x 190 cm (3’ x 6’3”).

Some mattresses will also be available in the standard European single mattress dimensions of 90 x 200 cm (3' x 6’6”).

Single beds are well-suited to singles, of course, and they can also be used by young children, teenagers, or university students 🎓

You can also easily combine two single mattresses to form one double bed, which is a great idea if you and your partner are of different body weights and have different mattress requirements.

The best thing about this mattress size is that you can store it easily and that it'll fit into any bedroom quite comfortably.

Small double mattresses sized 120 x 190 cm (4' x 6'3")

Small double mattresses fall between single mattresses and double mattresses.

These are a popular choice for teenagers, students, or young adults who want a little more luxury than a single mattress can offer but are not yet ready to invest in a double mattress.

Small double beds are often more convenient as you may not have enough room in your bedroom for a bigger-size mattress.

These are also convenient for spare rooms and make great guest beds.

Double mattresses sized 135 x 190 cm (4’6” x 6’3”)

The standard double mattress in Ireland has dimensions of 135 x 190 cm (4’6" x 6’3”).

Interestingly, the standard European double mattress is quite a bit larger and measures 140 x 200 cm.

We would recommend the standard double bed for singles wanting a bit more sleeping space and couples with limited space available in their bedroom.

Singles with pets (or single parents) will also find this mattress size quite comfortable.

King mattresses sized 150 x 200 cm (5’ x 6’6”)

A king-size mattress is our preferred choice for couples.

This mattress provides sufficient space for two people to sleep quite comfortably and not get in each other's way, especially if one partner is a restless sleeper.

Singles who like a lot of space will also really enjoy a king-size bed.

Interestingly, the closest European equivalent is either the European double mattress with dimensions of 140 x 200 cm or the European queen mattress with a size of 160 x 200 cm.

There is no standard queen size mattress in Ireland 👸

Super-king mattresses sized 180 x 200 cm (6’ x 6’6”)

A super-king-size mattress with dimensions of 180 x 200 cm is the premium choice for couples.

If you're sleeping on a super king-size bed, you'll have more than enough space to sleep comfortably without worrying that you'll disturb your partner's sleep.

Super-king mattresses are quite large, though, and often quite a bit more expensive, so these will not fit everyone's room or budget.

Emperor mattresses sized 200 x 200 cm (6’6” x 6’6”)

The emperor size is the largest mattress size available in Ireland.

This is definitely a luxurious choice that offers a lot of space and can be used quite comfortably by three people or more (parents and children).

Emperor beds may be the largest standard size but they are not commonly available as bed-in-a-box mattresses.

You'll be more likely to find them at traditional retailers.

They are also very expensive and not suitable for all budgets - or even all bedrooms.

Custom sizes

In addition to all of these standard Ireland bed sizes and European bed sizes, you'll also find oversized or extra-length mattresses, generally with lengths of 210 cm or 220 cm.

Other brands may offer custom bed and mattress sizes.

Not every mattress manufacturer will be able to accommodate custom sizes or oversized mattresses.

Luckily, you won't need these often.

But if you or your partner are very tall (over 2 metres), an oversized or extra-length mattress is a good idea.

You wouldn't want your feet sticking out at the end of your bed 👣

As a rule of thumb, the mattress you choose should be at least 20 cm longer than you are.

For example, if you are 190 cm tall, then your mattress should be at least 210 cm long.

The best mattress size for singles

Most people who sleep alone can sleep quite comfortably on the following sizes:

  • Single mattresses sized 90 x 190 cm
  • Small double mattresses sized 120 x 190 cm
  • Double mattresses sized 135 x 190 cm

We'd suggest opting for the 135 x 190 cm double size as this will be more comfortable, and give you enough space in case your personal situation changes or you happen to adopt a dog or need more space for Netflix marathons 📺

Children and adolescents will also be quite comfortable on these sizes, but may also opt for a small single mattress, depending on the size of their bedroom.

The best mattress size for couples

We recommend that couples choose one of the following sizes:

  • Double size mattresses 135 x 190 cm
  • King size mattresses 150 x 200 cm
  • Super-king size mattresses 180 x 200 cm

The double-size mattress would be the minimum as couples wouldn't be able to sleep comfortably on a smaller size, but, even then, we'd suggest choosing a king-size mattress or larger.

King-size mattresses give you enough space for a comfortable and restful sleep without disturbing your partner.

If your partner is quite restless or tends to end up lying crosswise, an even slightly larger mattress, like the super-king mattress, would be better.

If you have pets or children who like to hop into bed with you, then we'd definitely recommend a super-king size mattress or even an emperor bed, provided your bedroom is large enough.

The best mattress size for children

Mattresses for babies and small children under the age of 6 are considerably smaller at 60 x 120 cm or 70 x 140 cm.

Children sleep longer than adults, tend to be more restless, and require medium-firm support to allow for healthy growth and bone development.

A good child’s mattress should be able to accommodate all of this.

It’s also important to pay attention to how children’s mattresses are made: You wouldn’t want a mattress that contains harmful substances.

Of course, this is also something to consider when you purchase a mattress for yourself.

Small single or Irish single mattresses are popular with children above the age of 6.

We’ve summarised what to pay attention to when buying a mattress for your child in our article on the best mattresses for babies and children.

How do I choose the right-sized bed frame to match my mattress?

Bed frames are available in a range of different sizes to match your chosen mattress.

If you choose a king-size mattress, for example, you also need to purchase a king-size bed frame.

Some bed frames won't be available in smaller sizes, so it's always a good idea to check out bed frames and mattresses at the same time.

We've linked to some of our favourite bed frames below 👇


There are many different mattress sizes available - and you can easily find the one best for you!

We always recommend standard sizes as these allow you to find bed frames, box springs, and bed linen that will fit your mattress perfectly.

That said, a standard size may not be right for you and if you are still having problems choosing a mattress to suit your body, you can order a custom-sized mattress 📐

We always recommend that you get the right dimensions first but if you happen to have made a mistake, don't worry.

All of the bed-in-a-box mattresses we recommend come with free delivery and a money-back guarantee, so you can return the mattress if it's just not right for you.

Frequently asked questions

  • What is the best mattress size?

    There is no best mattress size, but there will be a size that's right for you.

    Consider the size of your bedroom, the space you have available around your bed, the other furniture in your bedroom, and how much space you need while sleeping.

    These factors will help guide you in determining what size bed is right for you.

  • What is the best mattress size for couples?

    We recommend that couples should opt for the 150 x 200 cm king-size bed.

    If there are no bedroom space constraints, then the 180 x 200 cm super-king mattress is also a great choice. 

  • How thick should my mattress be?

    The thickness of a mattress depends on its composition.

    If you buy a foam, memory foam, or latex mattress, we would recommend a mattress with a minimum thickness of 18 cm.

    For spring mattresses, we would recommend a minimum thickness of 23 cm

    Most bed-in-a-box mattresses have a height of 25 cm, though there a few thinner, lighter versions (like the Eve Lighter Hybrid) and a few thicker, more luxurious ones (like the DreamCloud Luxury Hybrid) available.

  • Can I place two mattresses next to each other to form one double bed?

    It used to be common practice to place two smaller mattresses next to each to form a double bed.

    This is highly recommendable for partners with a weight difference of 15 kg (33 lbs) or more or if you're choosing pure spring mattresses, which tend to have bad motion transfer.

    Choosing two smaller mattresses has the advantage that each partner can choose a mattress that's right for them, with their desired level of firmness.

    You can easily add a bed bridge to get rid of the gap between the two mattresses. 

  • What is the best bed frame size?

    There is no best bed frame size.

    Your bed frame, regardless of whether you're choosing a slatted base or a divan bed, should match the size of your mattress.

    Headboards are generally the same width as the bed frame.


My mum calls me "bear" because I like to sleep so much. I never knew that, one day, that would be a very useful skill. Can you tell that I've found my calling? 

You may also be interested in:

We have an affiliate relationship with some manufacturers, where we receive a commission on sales if you click over from our site. This does not affect the purchasing price. In contrast: By using our discount codes, you'll get the best deal possible.