The minimum size is 27 1/4” x 51 5/8” with a thickness not exceeding 6 inches.
Here’s where things get a bit wonky: There’s no such thing as a “universal fit” because while crib sizes are also regulated, their interior dimensions have a “plus or minus” tolerance from the standard 28” x 52 3/8” rectangle.
Snug = Safe
The goal is to have the crib mattress fit either very snug or moderately snug in the crib. A good rule of thumb is that no more than two fingers of space should exist between the side of the mattress and the crib frame. Any more than that, the crib mattress is too small and could be a suffocation and entrapment hazard.
Safety is Priority #1
Colgate Mattress® not only meets, but exceeds all government safety standards and we were instrumental in establishing additional, voluntary industry standards to keep babies safe. We take great pride in our craftsmanship and exacting manufacturing standards that have produced the world’s best crib mattresses since 1955.