Cot mattress buying checklist
- Measure the inside of the cot. The mattress should fit with no gaps.
- Choose firm, flat and waterproof. Your baby's head should sink no more than a few millimetres.
- Check for a fire-resistant label and the relevant British Standard.
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.
- The Lullaby Trust says your baby's head should sink no more than a few millimetres into the mattress.
- The Lullaby Trust recommends a new mattress for each baby where possible. A second-hand one should have a 100% waterproof cover, no rips, tears or water damage, no sagging, a good fit and a fire-resistant label.
- Mattresses: look for BS 7177:2008+A1:2011, and BS EN 16890:2017+A1:2021 for cot, travel cot and crib mattresses.
Related questions
What is a cot mattress?
A firm, flat mattress for a standard cot, usually 120 x 60cm.
Shop at Baby Kingdom
Browse cot mattresses 120 x 60
- Tutti Bambini Eco Fibre Cot Mattress (60 x 120 cm)
- Tutti Bambini Natural Coir Fibre Cot Mattress (60 x 120 cm)
- Ickle Bubba Premium Sprung Cot Mattress
- Obaby Fibre Mattress - 120 x 60cm
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More 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.