Choosing the Right Mattress for a Bunk Bed, High Sleeper or Cabin Bed

If you've just bought a bunk bed, high sleeper, mid sleeper or cabin bed – or you're replacing a worn-out mattress on one you already own – the mattress you choose matters more than it would on a standard single bed. Raised sleeping areas rely on guard rails set at a fixed height above the mattress surface, so getting the size and depth right isn't just about comfort, it's part of how the bed stays safe.

This guide covers exactly what to look for, and which of our own mattresses are suitable. For the fuller picture on mattress types, firmness and replacement guidance, see our Children's Mattress Buying Guide.

Why Bunk Beds, High Sleepers and Cabin Beds Need Special Consideration

Bunk beds, high sleepers, midsleeper cabin beds and cabin beds are all raised beds fitted with guard rails. Those rails are designed to sit a set height above the mattress surface – so a mattress that's deeper than the manufacturer's maximum reduces the amount of rail actually protecting your child, whichever of these bed types it's fitted to.

That's why we group mattresses suitable for all of these bed types together in one place: Bunk Bed Mattresses.

All of our mattresses are also tested to BS 7177, the British Standard covering resistance to ignition for mattresses, mattress pads, divans and bed bases. See our Bed Safety Standards & Testing page for full details on this and the standards that apply to the beds themselves.

What Size Mattress Do You Need?

Most of our bunk beds, high sleepers and mid sleepers take a standard single mattress in one of two sizes:

• UK single: 90 x 190cm
• European single: 90 x 200cm

Shorty and junior bunk beds are the exception – these typically need a shorter 70 x 160cm mattress instead. Always check the exact size stated on your bed's product page before ordering, as it varies by manufacturer.

Why Mattress Depth Matters

As a general rule, raised beds need a mattress no deeper than around 15-20cm, so the guard rails keep doing their job. Every mattress in our Bunk Bed Mattresses range is 15cm deep or less, so you don't need to check each one individually – anything in that collection is suitable on depth alone. Always double-check the maximum depth stated on your specific bed's product page too, since this can vary by manufacturer.

Which Mattress Should You Choose?

We stock two main styles suitable for bunk beds, high sleepers and cabin beds:

Kids Avenue Sprung & Pocket Sprung Mattresses

Fully-formed and ready to use straight out of the box. The Superior Sprung is an open coil mattress at 15cm deep; the Pocket Sprung uses individually pocketed springs for more targeted support, also at 15cm.

Sleeptight Rolled Mattresses

Delivered rolled and vacuum-packed, expanding to full size within around 24 hours of unpacking. Our Junior foam mattress is 14cm deep and available in both UK and European single sizes.

Whichever you choose, our full Bunk Bed Mattresses range is filtered to only show mattresses that fit the depth guidance above.

What About Trundle Beds?

If your bunk bed or cabin bed has a trundle underneath, it needs a shallower mattress so it can slide fully under the main frame. Our Trundle Mattress is just 10cm deep, purpose-built for this.

Buying a Bed and Mattress Together?

Many of our bunk beds, high sleepers, mid sleepers and cabin beds let you add a matching mattress at checkout for considerably less than buying one separately – look for the mattress options on the bed's own product page before ordering from the mattress range separately.

Frequently Asked Questions

What size mattress does a bunk bed need?

Most take a standard single mattress, either 90 x 190cm (UK single) or 90 x 200cm (European single). Shorty and junior bunk beds typically need a shorter 70 x 160cm mattress. Always check your specific bed's product page to confirm.

Can I use the same mattress on a high sleeper as a bunk bed?

Yes, in most cases. High sleepers, mid sleepers and cabin beds share the same core requirement as the top bunk of a bunk bed – a standard single mattress within the manufacturer's maximum depth. Our Bunk Bed Mattresses collection is suitable across all of these bed types.

How deep should a bunk bed mattress be?

As a general guide, no deeper than 15-20cm, so the guard rails remain effective. Every mattress in our Bunk Bed Mattresses range is 15cm or under.

Do I need a special mattress for a trundle bed?

Yes – trundle mattresses need to be shallower than a standard mattress so the trundle slides fully under the main bed. Ours is 10cm deep.

Final Thoughts

Getting the mattress right on a bunk bed, high sleeper, mid sleeper or cabin bed is about more than comfort – it's part of how the guard rails do their job. Stick to the correct size for your bed and a depth of 15cm or under, and you can choose confidently from our full Bunk Bed Mattresses range. For more on mattress types, firmness and general buying advice, see our Children's Mattress Buying Guide, and for full bed safety guidance, our Children's Bed Safety Guide.