What's the Difference Between a Single and a Small Double Mattress?
A UK single mattress is 90cm wide and 190cm long. A small double is 120cm wide and 190cm long. So the two are the same length, and the small double gives you an extra 30cm of width. That might not sound like much, but it can make a real difference to how comfortably you sleep and how you use your bedroom. In practice, it changes who the bed suits, what it fits into and how much room you have to move. This guide explains when each size makes sense, and what to check before you order.
The Sizes Side by Side
Size |
Width |
Length |
Also known as |
|---|---|---|---|
|
Single |
90cm |
190cm |
3ft |
|
Small double |
120cm |
190cm |
4ft, queen size bed |
For comparison, a standard double is 135cm wide, so a small double sits neatly between the two. Both the single and the small double share the same 190cm length, which means either will fit a standard-length room layout.
Who Suits a Single Bed?
A single is the classic size for a child's room, a bunk or cabin bed, a guest room where space is tight, or a box room used as an office and a spare bed. At 90cm wide, it's the size that fits where nothing else will.
It's worth choosing the mattress depth carefully for a single. If it's going on a bunk or cabin bed, safety regulations call for a shallower mattress, and our Hybrid® Kids Mattress is 16cm deep for exactly that reason. For a standard single bed frame, any of our Hybrid® mattresses will work.
Who a Small Double Suits
A small double is a good choice when you want more room to stretch out than a single offers, but don't have enough space for a standard double. It's ideal for:
- Teenagers and older children, who benefit from the extra room to stretch out as they grow
- Guest rooms, where a single guest gets a generous bed and a couple can still manage for a night or two
- Studio flats and smaller bedrooms, where a full double would leave no space to walk around
- Anyone who sleeps alone and likes room to move, particularly side sleepers and people who change position often
Because the width is the only thing that changes, a small double gives you noticeably more comfort for very little extra floor space.
Room to Move
Sleep isn't still. Most of us turn over many times a night, and a mattress that's too narrow can leave your shoulder or elbow hanging over the edge. The extra 30cm of a small double makes turning over easier, and it's the width where many adults stop noticing the edge of the bed at all.
That's especially true with a mattress that supports you right to the edge. Our Hybrid® Pro and Hybrid® Luxe sit on a SupportCore™ sprung base with firm edge-to-edge support, so you can use the whole width of whichever size you choose.
What to Measure Before You Choose
- The bed frame. A mattress has to match the frame exactly, so check whether the frame you have, or the one you're buying, is a single or a small double. Our beds are available in Single, Double, King and Super King, and selected mattresses and toppers come in Small Double as well.
- The room. Allow space to walk around the bed and open doors and drawers. A small double needs 30cm more width than a single, which is worth marking out on the floor.
- The bedding. Single bedding won't fit a small double, and standard double sheets will be loose on it, so budget for the right size. Our mattress protectors are available in Small Double.
- Access. Our Hybrid® mattresses arrive rolled in a box, which makes both sizes easy to get up narrow stairs.
Which Simba Mattress Is Right for You?
Every Simba mattress is designed to feel medium-firm, with a cradled feeling in the top layers and firmer support in the base. That's the same whether you choose a single or a small double, so the decision comes down to your budget and how much cooling you'd like. You'll find every size of our Hybrid® mattresses, including single and small double, on one page.
A few pointers by situation:
- For a child's standard bed, the Hybrid® Essential is light, 20cm deep and has our signature Aerocoil® microsprings and Simbatex® foam.
- For a teenager, the original Hybrid® in a small double gives them room to grow into, and the extra support they need for their changing shapes.
- For a guest room, the Hybrid® Essential or Hybrid® in either size is a great fit.
- For a small main bedroom, the Hybrid® Pro in a small double features a double layer of Aerocoil® microsprings for responsive support, plus a breathable wool top layer that helps hot sleepers stay comfortable
Making the Most of Either Size
Not ready to buy a new mattress? Our toppers come in both single and small double sizes, giving you an easy way to refresh the feel of your existing mattress. A mattress protector can also help keep your mattress clean and protected, and our TripleShield protectors fit mattresses up to 40cm deep. Every new Simba mattress comes with a 200-night trial and a 10-year guarantee, so you have time to get used to your new mattress and make sure it's right for you.
FAQs
In the UK, “queen” is sometimes used to describe a 120 x 190cm small double. However, mattress sizes and naming conventions vary between countries, and a queen-size mattress in many European markets can have different dimensions. Always check the measurements in centimetres before buying to make sure your mattress fits your bed frame.
They can for occasional use, which is why a small double can work well in a guest room. For two adults sharing a bed regularly, a double or king provides considerably more space, with a king offering more room per person than a double.
No. The mattress and the frame need to be the same size, otherwise you'll have a 30cm gap and the mattress won't be supported properly.
Our bed frames are available in Single, Double, King and Super King sizes. We offer selected mattresses in Small Double, along with all our mattress toppers. Fitted sheets aren't available in Small Double, so check the dimensions of your existing bedding before choosing this mattress size.
