Can a toddler use a cot bed mattress in a toddler bed?
Short answer: Often, yes. Many toddler beds take the same 140 x 70cm size as cot beds, but check the bed's stated mattress size before you buy.
Here is the detail behind that answer, taken from current UK guidance from the NHS and the Lullaby Trust.
Things to check
- Check the mattress size it takes and buy a mattress that fits snugly.
- Side guards help stop your child rolling out in the early weeks.
- A low height makes it easier to climb in and out on their own.
What the guidance says
- Use a firm, flat, waterproof mattress in good condition, with no raised or cushioned edges, that fits the cot or Moses basket with no gaps.
Related questions
What is a toddler bed?
A low bed sized for a cot-bed mattress (often 140 x 70cm), usually with side guards, for children moving out of a cot.
Shop at Baby Kingdom
- Flair Imogen Montessori Toddler Floor Bed with Safety Fence Lilac
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- Hoppekids Shorty Bunkbed
- Flair Oliver Car Wooden Bed White & Oak
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
What size mattress does a toddler bed take?Can a toddler bed hold an adult?Can I buy a second-hand toddler bed?Do I need a toddler bed?Your 2 year's sleep space: a safe-sleep guideToddler beds buying guide for UK parentsAll toddler beds and big-bed moves advice →
Sources
- The Lullaby Trust: Baby mattresses and bedding (accessed 2026-10-21)
General information only, not medical advice. Always follow your product's instructions. If you are worried about your baby, contact your GP, health visitor or 111. In an emergency, call 999.