Choosing the right mattress size is one of the most important parts of creating a comfortable bedroom. The right size affects how much room you have to sleep, how well the bed fits your space, and whether your bedroom still feels easy to move around in.
At Emerald Rest, we supply mattresses and beds in the most popular Ireland and UK sizes, including Single mattresses, Small Double mattresses, Double mattresses, King size mattresses and Super King size mattresses.
This guide explains each mattress size, who it is best suited for, and what to consider before choosing your new bed or mattress.
Standard Mattress Sizes in Ireland and the UK
Most mattresses sold in Ireland and the UK follow standard sizing. Below is a simple guide to the main mattress sizes available from Emerald Rest.
| Mattress Size | Dimensions | Best For |
|---|---|---|
| Single Mattress | 3ft x 6ft3 / 90cm x 190cm | Children, teenagers, guest rooms and smaller bedrooms |
| Small Double Mattress | 4ft x 6ft3 / 120cm x 190cm | Single adults who want more room, or compact double bedrooms |
| Double Mattress | 4ft6 x 6ft3 / 135cm x 190cm | Couples, main bedrooms and everyday comfort |
| King Size Mattress | 5ft x 6ft6 / 150cm x 200cm | Couples who want extra width and length |
| Super King Size Mattress | 6ft x 6ft6 / 180cm x 200cm | Larger bedrooms and maximum sleeping space |
If you are replacing an existing mattress, always check the size of your current bed frame or divan base before ordering. A mattress that is too large or too small will not sit correctly and may affect comfort and support.
Single Mattress Size
A Single mattress measures 3ft x 6ft3, or 90cm x 190cm. This is one of the most popular choices for children’s rooms, teenagers, guest rooms and smaller bedrooms.
A Single mattress gives one person enough space to sleep comfortably without taking up too much floor space. It is also a practical choice if you are furnishing a spare room or need a simple bed setup for everyday use.
For a complete setup, you can pair a Single mattress with one of our Divan Bed Sets, Divan Bases or Upholstered Beds.
Small Double Mattress Size
A Small Double mattress measures 4ft x 6ft3, or 120cm x 190cm. It is sometimes called a three-quarter bed and is a good option when you want more room than a Single but do not have space for a full Double.
Small Double mattresses are especially popular for single adults, teenagers who want extra comfort, guest bedrooms, and smaller apartments. They can also work well in rooms where a Double bed would feel too tight.
If storage is important, a Small Double mattress can work well with an Ottoman Bed or a divan base with drawers, helping you make better use of your bedroom space.
Double Mattress Size
A Double mattress measures 4ft6 x 6ft3, or 135cm x 190cm. This is one of the most common mattress sizes in Ireland and the UK, and it is a popular choice for couples and main bedrooms.
A Double mattress gives enough space for two people while still fitting comfortably in most standard bedrooms. It is also a good choice for single sleepers who like extra room to stretch out.
Many customers choose a Double mattress as part of a full Divan Bed Set, as this gives you the mattress, base and matching headboard in one complete package.
King Size Mattress
A King size mattress measures 5ft x 6ft6, or 150cm x 200cm. It is wider and longer than a Double, making it a strong choice for couples who want extra comfort and more room during the night.
The extra length can also make a King size mattress a better option for taller sleepers. If your bedroom has the space, upgrading from a Double to a King size can make a noticeable difference to sleep comfort.
A King size mattress works beautifully with our Upholstered Bed Frames, Ottoman Beds and Divan Bed Sets.
Super King Size Mattress
A Super King size mattress measures 6ft x 6ft6, or 180cm x 200cm. This is the largest standard mattress size and gives the most sleeping space.
Super King size mattresses are ideal for larger bedrooms, couples who prefer plenty of room, or anyone who wants a more luxurious sleep setup. They also work well if children or pets sometimes climb into bed.
Because a Super King size mattress is larger, it is important to measure your bedroom carefully before ordering. Check that you have enough space around the bed for bedside tables, wardrobes, drawers and easy movement.
How to Choose the Right Mattress Size
When choosing your mattress size, think about your room size, who will be sleeping in the bed, and how much space you like while sleeping.
- For children or smaller rooms: a Single mattress is usually the most practical choice.
- For one adult wanting more space: a Small Double mattress gives extra comfort without taking over the room.
- For most couples: a Double mattress is the standard option.
- For couples wanting more comfort: a King size mattress gives extra width and length.
- For maximum space: a Super King size mattress offers the most room and a more premium feel.
As a general rule, choose the largest mattress that comfortably fits your room without making the space feel cramped.
Should You Buy a Mattress on Its Own or as a Bed Set?
If your existing bed base is still in good condition, you may only need to replace the mattress. In that case, you can browse our full range of Mattresses and choose the size and comfort level that suits you best.
If you are updating the whole bedroom, a complete Divan Bed Set can be better value. This gives you the base, mattress and upholstered headboard together, helping you create a finished look without having to match separate pieces.
For bedrooms where storage is important, an Ottoman Bed is also worth considering. Ottoman beds lift up to reveal storage underneath, making them ideal for spare bedding, clothes and everyday bedroom storage.
Final Mattress Size Tips
Before ordering your new mattress, measure your room and check the space around where the bed will sit. Make sure there is room to walk around the bed and open drawers, wardrobes or bedside units easily.
You should also check the size of your existing bed frame or base if you are only replacing the mattress. A 4ft6 Double mattress needs a 4ft6 Double base, a 5ft King size mattress needs a 5ft King size base, and so on.
At Emerald Rest, we offer a wide range of mattresses, divan bed sets, ottoman beds and upholstered beds, with free 2-man delivery across Ireland.