Trundle Bed and Guest Bed Mattress Sizes
A trundle bed mattress size is almost always based on a standard single (90x190cm / 3ft) or small single (75x190cm / 2ft6). Most UK trundle and guest beds are designed around these two dimensions so the pull-out section slides neatly underneath the main bed without wasting space or requiring custom mattresses.
Standard UK Trundle Bed Mattress Sizes
Trundle beds and most guest beds sold in the UK accept one of two mattress sizes. The main bed is usually a single 90x190cm while the trundle drawer takes either another single 90x190cm or a small single 75x190cm. This keeps the overall footprint compact and allows the lower bed to tuck away completely when not in use.
Always measure the internal dimensions of the trundle frame before buying. Subtract at least 2cm from length and width to allow the mattress to fit without compressing against the sides. Depth is equally important: most trundle systems state a maximum mattress depth so the drawer still closes. Use the exact maximum depth given by the manufacturer.
Common Trundle Configurations
- Main bed single (90x190cm) with trundle small single (75x190cm) – the most space-efficient option for children’s rooms.
- Main bed single (90x190cm) with trundle single (90x190cm) – gives two identical sleeping spaces but the drawer is deeper and the bed wider overall.
- Daybed-style trundles that convert into a small double when both sections are pulled out side-by-side (typically two 90x190cm mattresses placed together).
See the full selection at Trundle Beds to compare frame depths and internal measurements.
Guest Bed Mattress Sizes and Folding Options
Guest beds, including metal guest beds and folding beds, follow similar sizing rules. Most accept a standard single mattress 90x190cm. Some folding guest beds are designed for a shorter EU single 90x200cm, so check the exact product page. Metal roll-out trundles are often sold without a mattress and are built to take a 90x190cm single of up to a stated maximum depth.
When choosing a mattress for a guest bed that folds away, select a thinner profile so the unit remains easy to store and move. A memory foam or pocket sprung single mattress works well because it can be rolled or folded slightly if needed, although UK fire-safety rules still apply.
Browse practical options in Guest Beds or the metal versions at Metal Guest Beds.
Children’s Trundle and Cabin Bed Mattress Guidance
Many children’s trundle beds are built into mid-sleeper or cabin bed frames. These usually take a single 90x190cm mattress on the top and either a matching single or small single on the pull-out. Top bunks and mid-sleepers must meet BS EN 747; the guard rail must rise at least 16cm above the mattress surface, so use the maximum mattress depth the bed maker states and never exceed it.
For younger children, some cabin beds incorporate a trundle that accepts a cot bed size 70x140cm. This is useful when transitioning from a cot (common size 60x120cm) to a toddler bed. Always confirm the listed maximum mattress depth on the specific bed page.
Popular children’s models include the Flair Ellis Single Bed with Trundle which pairs neatly with a standard single mattress, and the Flair Aurora Daybed with Trundle that works with two single mattresses when extended.
Choosing the Right Mattress Type for a Trundle
Because trundle mattresses are stored horizontally under a bed, breathability and moisture control matter. A good choice is a medium-firm sprung or memory foam single mattress that recovers its shape quickly after being stored. Avoid very thick mattresses (deeper than the frame allows) as they will prevent the drawer from closing.
Consider adding a mattress protector to guard against spills, especially useful on guest or children’s trundles. A thin mattress topper can also fine-tune firmness without increasing overall depth beyond the limit.
For reliable performance look at Maxitex or Noomi single mattresses; check the exact depth on the product page to confirm it fits your chosen trundle frame.
Practical Checklist Before You Buy
- Measure the internal length and width of both the main bed and the trundle drawer.
- Note the manufacturer’s stated maximum mattress depth for the trundle section.
- Decide between small single (75x190cm) or single (90x190cm) based on available space and who will use the lower bed.
- Confirm the bed meets UK fire-safety regulations (BS 7177 for mattresses).
- If buying for a child, verify the top-bunk or mid-sleeper guard rail will still exceed 16cm once your chosen mattress is fitted.
- Check whether the trundle has its own legs or uses the floor; this affects the ideal mattress depth.
Compare different sizes and styles on the Beds main category or narrow down by age group with Kids’ Beds.
Trundle Mattress Size Comparison Table
| Mattress Type | Dimensions | Typical Use in Trundle | Notes |
|---|---|---|---|
| Small Single | 75x190cm (2ft6) | Lower trundle drawer | Most compact, easiest to store |
| Single | 90x190cm (3ft) | Main bed or matching trundle | Standard UK size, widely available |
| Cot Bed / Toddler | 70x140cm | Younger child trundles | Shorter length, check frame compatibility |
| EU Single (occasional) | 90x200cm | Some folding guest beds | Longer than UK single – measure carefully |
EU sizes differ from UK sizes, so an EU double (140x200cm) will not fit a standard UK trundle designed for 135x190cm. Always use the UK sizes listed above unless the product page explicitly states otherwise.
Trundle beds remain one of the most practical ways to add occasional sleeping space without sacrificing floor area during the day. By matching the mattress precisely to the frame dimensions you avoid wasted money on mattresses that do not fit and ensure safe, comfortable sleep for guests or siblings.
Our picks for this guide
- Flair Ellis Single Bed with Trundle Beige Woven Fabric – Accepts standard single 90x190cm mattresses on both levels and the trundle drawer is designed to close fully with mattresses up to the stated maximum depth.
- Flair Aurora Daybed with Trundle Khaki Green Velvet – Daybed format allows two single 90x190cm mattresses to be used side-by-side when extended, ideal for occasional guest use.
- Flintshire Furniture Hendre Wooden Guest Bed with Pull Out Trundle White – Classic wooden guest bed built specifically for a single mattress on the main frame and a small single or single on the pull-out trundle.
- Maxitex Premier Sprung Mattress – Reliable sprung mattress available in single sizes that fits most trundle frames while meeting UK fire safety standards.
Frequently asked questions
Can I use a double mattress on a trundle bed?
No. UK trundle beds and guest beds are built for single (90x190cm) or small single (75x190cm) mattresses. A double 135x190cm is far too wide for the drawer mechanism and will not slide underneath. Choose two single mattresses only if the daybed design allows them to be placed side by side when extended.
What depth mattress fits under a trundle bed?
Depth depends on the specific frame. Most manufacturers state a maximum mattress depth on the product page. Exceeding this prevents the drawer from closing flush. Always use the exact maximum depth listed for that model.
Is a small single mattress suitable for a guest trundle?
Yes, a 75x190cm small single is often the best choice for the lower trundle because it leaves clearance on the sides and allows the drawer to close easily. It is still a practical length for most adults staying overnight, especially when paired with a memory foam or pocket sprung top layer.
Do trundle beds need special mattresses?
No special construction is required beyond meeting UK fire safety rules (BS 7177). However, choose a mattress that is not excessively thick and that regains its shape after being stored flat. Most standard single mattresses from brands such as Maxitex or Noomi work well.
Can children under 6 sleep on the top bunk of a trundle cabin bed?
The British Standard BS EN 747 states that top bunks are not recommended for children under 6 years old. The guard rail must be at least 16cm above the mattress surface; always use the maximum mattress depth stated by the bed maker to keep the rail height compliant.