Knowledge Guide™ · Household
What mattress should a child sleep on?
Firmness, thickness, safety and how long a kid's mattress should last.
Key points
- • Medium-firm, roughly 6–7 out of 10
- • 6–8 inches thick for bunk beds, guardrail clearance of 5 inches
- • A full often outlasts a twin as the child grows
- • Waterproof protector, plus a spare
Why firmer is right for children
Children weigh little, so they compress comfort layers far less than adults. A mattress that feels plush to a parent can feel like quicksand to a forty-pound sleeper. Firmer surfaces are also safer for the youngest children, where soft bedding is a known risk.
Bunk beds and safety
Bunk manufacturers specify a maximum mattress thickness for a reason. If the mattress raises the sleeping surface too close to the guardrail, the guardrail stops working. Measure from the top of the mattress to the top of the rail and confirm at least five inches.
Twin or full?
A full costs modestly more but lasts through the teen years and converts to a guest bed afterward. Choose twin only when the room genuinely cannot fit a full with walking clearance on the open sides.
Common questions
Compare your options
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