You want your baby to have a safe sleeping space and one important part of that is to have a crib mattress that correctly fits your crib. But how do you know if your crib mattress fits correctly?
Cribs sold in the USA have standardized size requirements. Crib mattresses are designed to fit snugly inside a crib. The best thing to do is to measure your crib to make sure it is in compliance. If it is, you should have no issue fitting a crib mattress snugly inside.
How do I measure my crib?
Measure the INTERIOR of your crib to the below specifications. If your crib measures any smaller or larger, you need to contact the crib manufacturer as your crib is not made to legal specifications.
Crib dimensions are dictated by ASTM and Federal Law. The dimensions in the crib standard require cribs to have interior dimensions of 28 +/- 5/8 inches wide and 52 3/8 +/- 5/8 inches long.
The inside of your crib should measure somewhere between 27 3/8 to 28 5/8 inches wide and between 51 ¾ and 53 inches long. Mattresses are designed to be slightly smaller to allow them to fit within these tolerances.