mattress for crib

Ok, so this is a silly question.....

We ordered our crib from Jcpenney and the mattress, but I was just looking at the specks on the size the mattress and it's shorter then the length of the crib....

Should I order one that is the same length??

I didn't think to check it out since it said fits most cribs....

Re: mattress for crib

I think the mattress should be one inch smaller in both length and width than the opening in the crib, so you can tuck the fitted sheet in.... make sure to keep it centered in the crib though...(baby bargains tip #812)