mattress firm

The listings show mainly firm and medium-firm feels, plus several 2-stage two-sided options that provide a firmer infant side and a softer toddler side (firm/soft two-sided).

Crib and toddler mattresses in these listings follow standard full-size crib dimensions—about 51.63–52 inches long and roughly 27.25–28 inches wide. Thickness most commonly falls in the 4–6 inch range.

Many foam and baby mattresses ship compressed or rolled in a box. After unrolling, descriptions commonly recommend allowing about 48 hours (some list up to 48–72 hours) for the mattress to fully expand.