How Should A Crib Mattress Fit According To Experts

The quick answer on how should a crib mattress fit is it shouldn’t have any space or gap. There are simple ways to ensure the best fit, and this article will share them below. Remember that it can be confusing to buy a mattress size, even the ones we use on the crib.

Speaking of size, we have created a complete crib mattress size guide for you to read. Would you mind reading that to help you understand the fitting tips better? 


Everything To Know About How Should A Crib Mattress Fit

A crib mattress should fit snugly on the crib. This means that there are no gaps throughout the sides, and you can’t fit your two fingers in them when the mattress is on the crib. You can also check if the panels at the end of the crib extend below the mattress to avoid the risk of suffocation or entrapment when your child moves around. 


How Do I Know If A Crib Mattress Will Fit?

When buying a crib mattress, please write down the dimensions of your crib to ensure that the bed won’t be too big or too small for it. Then, do the two-finger test by inserting two fingers between the mattress side and the crib. If you can fit them through the gap, then you must get a bigger bed. In general, you want the crib mattress to be so close-fitting to the crib that even setting it up becomes tasking. 


How High Should The Crib Mattress Be For A Newborn?

Newborns are still immobile, which means placing the crib mattress in the highest position is still safe for them. In addition, putting the crib mattress at the highest setting will make it easier for you to support and lift your baby in and out of the crib. You can also check if the crib mattress is at the maximum of 26 inches below the crib mattress rail when you put it at the highest position. 

By five to eight months of age, your baby will typically know how to sit up or push onto his knees or hands. At this milestone, you can set the mattress a notch down to keep your baby from pulling himself up. And according to The Nemours Foundation, you can put the crib mattress at the lowest position once your child can stand. 


How to set up a safe crib

According to the National Home Safety Alliance, you should ensure that the crib mattress does not only fit well into the crib. It should also be firm enough that there will be no indentation when your baby uses the pad. Furthermore, use the correct size mattress sheet because the loose material can pose a choking hazard on your baby. 


What Is The Standard Size For A Crib Mattress?

The standard crib mattress size is 27 and 1/4 inches for its width and 51 and ¼ inches for its length. It’s also worth noting that the maximum recommended thickness for a crib mattress is 6 inches. However, there are other crib mattress sizes available in some stores.

To help you achieve the safest fit, which is snug, write down the dimensions of your crib and use it when selecting a crib mattress. Furthermore, remember that there are other shapes of cribs. Get the proper shape mattress for these models, typically smaller than the standard crib mattress size. 


Are Crib And Toddler Mattresses The Same Size?

Crib and toddler mattresses usually have the exact dimensions of 28 by 52 inches if you round up the extra ¼ inch of the standard size. Therefore, it’s common for parents to transfer the same crib mattress onto a toddler bed once their child transitions. Still, it’s worth checking if the toddler bed and crib mattress dimensions will work together. 

However, consider that you’re putting a mattress that’s supposed to be used with rails. Therefore, it will sit closer to the ground if you put the crib mattress on a toddler bed. Furthermore, your toddler may point out that the crib bed feels too stiff for his comfort. 


Are crib and bassinet mattresses the same size?

A crib and a bassinet mattress won’t have the same size because bassinets are smaller than cribs. A bassinet mattress is an oval or rectangular pad that is 15 to 18 inches wide and 30 to 33 inches long. If you want to know more about this type of product, here is where to buy a bassinet mattress.


How Do I Know If My Crib Is Too Small?

Check the interior dimensions of your crib to see that it meets the regulations dictated by the Federal Law and ASTM. For example, the standard crib size should be 28 inches wide and 52 and ⅜ inches long so the crib mattress will fit within it. You should also know when to drop the crib and move your child to a bed once the crib side rail is less than 75% of his height. 



And that’s it! We just learned how should a crib mattress fit according to experts’ recommendations. First, it should fit snugly in the crib so that you can’t insert two fingers on the sides. 

We hope this size guide helps you find the best and safest mattress for your little one’s crib. Leave a comment if you have any more questions!

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