Single or Small Double Bed for a Child: Which Size Should You Choose?

Choosing between a single and small double can sound fairly straightforward until you start measuring your child's bedroom. A small double gives them an extra 30cm of mattress width, which can seem like an obvious upgrade, but that additional width has to come from somewhere in the room.

In a spacious bedroom, you might barely notice the difference. In a smaller one, those 30cm could affect where you position a bedside table, how easily the wardrobe opens or whether there's enough room for a desk later.

Rather than simply asking which bed is better, it helps to think about where that extra space will be most useful. For some children, the additional mattress width will be well worth having. For others, keeping more usable space around a single bed will make the whole bedroom work better.

Single and Small Double Sizes Compared

The first thing to know is that you're not gaining any additional length by choosing a small double. Both sizes take a mattress measuring 190cm long, so the difference is entirely in the width.

For a child who is comfortable in a standard single wooden bed, moving to a small double isn't about accommodating extra height. You're choosing to give more of the bedroom over to the bed in return for a wider sleeping space.

Whether that's worthwhile depends much more on the room and how your child uses it than on the mattress dimensions alone.

When a Single Bed Makes More Sense

A single is easy to underestimate because it's the smaller of the two options, but for plenty of children's bedrooms it's simply the size that makes the most sense.

Think about a smaller bedroom with a wardrobe along one wall, drawers against another and toys, books or belongings that all need somewhere to live. As your child gets older, you may also need to find room for a desk or additional storage. A 90cm-wide mattress keeps more of the available floor space free for everything happening around the bed.

A single can be particularly practical when:

• Space beside the bed is already fairly limited.
• Your child needs plenty of usable floor space.
• Several pieces of furniture need to share the room.
• You're likely to add a desk as they get older.
• Moving to a 120cm-wide mattress would make the layout feel cramped.

There's nothing inherently temporary about choosing a single bed either. At 190cm long, a standard UK single mattress is the same length as both a small double and a double.

If the bedroom has a better layout with a single, squeezing in a larger bed simply because the floor dimensions allow it may not be the best use of the available space. A room that feels comfortable and gives your child space for everything else they do there can be more useful than an extra 30cm of mattress width.

When a Small Double Is Worth the Extra Space

The calculation changes in a bedroom with a little more breathing room. If the wardrobe opens comfortably, there's plenty of space to move around and adding another 30cm to the mattress won't force other furniture into awkward positions, a small double wooden bed becomes an attractive option.

For an older child or teenager in particular, the extra width gives them noticeably more sleeping space without increasing the 190cm mattress length. It can also make sense when you're replacing a smaller childhood bed and want the next frame to work well as their bedroom becomes more grown-up.

The main consideration is whether the bedroom can comfortably absorb the wider footprint. In a larger room, the difference may have very little effect on the overall layout, making the additional mattress space an easy choice. If furniture has to be moved into less practical positions or the room suddenly becomes difficult to navigate, the benefits are less clear.

What Does 30cm Look Like in a Bedroom?

Thirty centimetres is roughly the width of a standard school ruler, which is much easier to visualise than simply comparing 90cm and 120cm on a product specification.

If you're undecided, take a tape measure into the bedroom and mark out the external dimensions of both bed frames. Don't rely on the mattress measurements alone, as the complete wooden frame will be larger.

Once you've marked out both options, you can see exactly what the wider bed would mean for the rest of the room. In some bedrooms, giving up that extra strip of floor space will make very little difference. In others, you may find it's more useful beside the bed, around existing furniture or simply as open space.

It's a simple exercise, but it gives you a much better idea of whether the extra mattress width is genuinely worth having. Sometimes a small double will fit comfortably and the decision becomes easy. Sometimes marking it out makes it equally clear that the room will work better with a single.

Which Size Works for Different Bedrooms?

Measurements only tell you so much. It can be easier to make the decision when you think about what else needs to happen in the bedroom alongside sleeping.

A smaller bedroom with lots to fit in

When wardrobes, drawers, toy storage and other furniture are already competing for space, a single will often give you more freedom with the layout. You can still provide a full-length bed without allowing it to dominate the room.

This can be particularly useful for younger children who spend a lot of time playing in their bedroom. Keeping an extra 30cm of floor space available might not sound significant, but it becomes much more valuable when added to the space around the rest of the furniture.

A larger bedroom with room to spare

If a small double fits without compromising the layout, the extra sleeping space can be a worthwhile addition. This is especially true when the bed is likely to remain in the room for many years.

You don't necessarily need to fill a larger bedroom with a bigger bed, but there is little benefit in choosing a single purely to save space that isn't needed elsewhere. Marking out both sizes should give you a good indication of whether the wider frame feels in proportion with the room.

A bedroom that needs a study area

For school-age children and teenagers, the desk can become just as important to the layout as the bed.

If you're likely to add one in the next few years, work out where it could go before committing to a small double. A single may leave enough room for a proper desk and chair without requiring another complete rearrangement later.

Where the bedroom comfortably accommodates both, the choice becomes much easier. Your child can have the extra width of a small double without losing a useful study area.

A child approaching their teenage years

This is probably where parents are most likely to hesitate between the two sizes.

A small double can be appealing if there's sufficient room because it provides a more generous sleeping space that can remain suitable throughout the teenage years. However, a standard single is also full adult length, so there's no need to move up a size simply because your child is getting older.

The room still gets the deciding vote. If a small double fits comfortably, it can be a great longer-term choice. If it overwhelms the available space, a single remains a perfectly practical option.

Think About What Else Might Change

The bed may stay in the same place for years, but very little else in a child's bedroom is guaranteed to do the same. Toy boxes disappear. Desks arrive. Wardrobes get fuller. Shelving changes. Your child may decide they want somewhere to sit with friends, or simply prefer having more open space as they get older.

You can't predict every version of the bedroom, and there's no need to try. What you can do is avoid creating a layout that only just works today!

If choosing a small double leaves virtually no flexibility around the remaining furniture, a single may give you more options later. Where there's already plenty of spare floor space, the wider bed is less likely to restrict how the room develops.

This is also why it's worth looking beyond the dimensions of an empty bedroom. Think about the furniture that's staying, anything you're likely to add and how easy it would be to rearrange things without replacing the bed.

So, Single or Small Double?

There isn't a particular age when a child should move from a single to a small double, and choosing the larger size isn't automatically an upgrade. A single is likely to make more sense if bedroom space is limited, you want to preserve room for playing or studying, or the additional 30cm would make the furniture layout noticeably tighter.

A small double becomes more attractive when the room can comfortably accommodate it and you'd like to give an older child or teenager a wider sleeping space without moving to a full double.

If you're still caught between the two, come back to the simplest question in this guide: what would your child gain more from, another 30cm of bed or another 30cm of bedroom? The answer tends to become much clearer once you've measured the room.

Made for Their Bedroom

Whichever size you settle on, the bed itself shouldn't dictate what your child's bedroom has to become.

At The Wooden Bed Company, we make our beds to order in Yorkshire from solid European oak or Scandinavian pine. Rather than designing children's beds around short-lived themes, we've kept them simple, giving you a solid wooden frame that can sit happily through new bedding, new wall colours, furniture changes and all the different versions of their bedroom still to come.

Explore our single wooden beds and small double wooden beds to compare the options and find the size that works best for the space you actually have.