What Everyone Ought to Know about Standard Crib Mattress Sizes

Get the right crib mattress for your standard crib. A wrong crib mattress can easily cause your infant to suffocate! Read below for the standard crib mattress sizes and an easy to follow summary at the end...

Standard Size Crib Mattress

You’ll be hard pressed to find a crib mattress that won’t fit a standard crib size, but manufacturers do vary on the length and width of the actual mattress. Be very clear on the following lengths and widths.

The length and width of your crib mattress must be:

• Length: 51 and 5/8 inches
• Width: 27 and 1/4 inches

The thickness of the mattress isn’t as critical to the safety of your child, but you need to have a crib sheet that fits very well. Your crib sheet should go over the corners of the mattress so you can tuck it underneath without any slack. If your mattress isn’t slack, your child can crawl underneath the mattress and suffocate!

Your crib mattress must have the following depths to be standard:

• Smaller than or equal to 6 inches
• Foam mattresses: Between 4 to 6 inches
• Coil mattresses: Between 5 to 6 inches

Non Standard Crib and Mattress

These generally come as a set. Although I don’t recommend it, if you’re going this route, here is the checklist to ensure your child stays safe:

1. Do the “two finger test” and the "squeeze test"
2. Make sure the sheets are tucked securely underneath the mattress with no slack
3. Make sure there are no crib bumpers

Conclusion

Buy a crib mattress that is:

1. Length: 51 and 5/8 inches
2. Width: 27 and 1/4 inches
3. Thickness: Less than or equal to 6 inches
4. Passes the "finger test” and "squeeze test"