Choosing a crib and crib mattress is about far more than picking the right style and size. It’s also about safety, and protecting what matters most. Ultimately, the right crib mattress should fit the crib properly, feel firm, and provide a flat, safe, and supportive sleep surface for your new baby.
If you are still starting with the sizing question and deciding what type of crib is right for you, we recommend reading our discussion on crib sizes, crib types and their compatible mattresses. It covers everything from standard crib mattress dimensions to the differences between full-size, mini crib, and portable cribs.
Today’s guide focuses more on how to choose the right crib mattress with an emphasis on safety, and how to know that it is a good, safe, fit for your crib and your baby. Keep reading for our steps to get started.
1) Check for the Proper Fit
First, the mattress should fit the crib properly, with as little space around the edges as possible. In particular, a mattress that is too small can leave dangerous gaps between the mattress and the crib frame that can be an entrapment risk for infants.
One of the easiest and most common ways to check the fit between a crib and crib mattress is the two-finger test.
To do the two-finger test:
- Place the crib mattress inside the empty crib
- Push it fully into one corner
- Check the space between the mattress and the crib frame on the other sides
If the gap anywhere around the mattress is more than two-fingers’ width, the mattress is too small for the crib. This is a simple check to do, but a critically important one.
2) Check for the Proper Firmness
In addition to the size and fit, it is important to check the crib mattress’ firmness. Please note that a crib mattress should feel much firmer than a typical mattress for adult sleepers. What feels too firm to most adults is often the ideal level of support for a newborn or infant.
A crib mattress should feel supportive and should not feel plush or overly padded. A mattress that is too soft can create an unsafe sleep surface, because it can lead to both rollover and suffocation risks. The firmer the mattress, the easier it is to help provide the safe, flat, and supportive surface babies need.
To check the firmness of a crib mattress, press down hard in the center and along the edges of the mattress. It should feel firm and snap back quickly, not hold the impression of your hand. If the surface of the crib mattress feels too soft or if it returns to form too slowly (similar to a deep-contouring, slow-moving memory foam), it is not firm enough.
3) Inspect the Surface
Lastly, on top of having the proper fit and firmness, a safe crib mattress should also provide a consistent, flat surface across the entire sleeping area. Parents are advised to avoid any mattress that appears uneven, sagging, lumpy, or worn down. This step is especially important if you are considering reusing a hand-me-down crib or crib mattress from an older sibling.
Remember, the crib mattress needs to be perfectly flat. To check, simply run your hand over it to feel for any sagging, weird soft spots, or other signs of wear.
Crib Mattress Safety FAQs
Ultimately, by verifying the fit, feel and firmness of the mattress, you’re creating the secure environment your baby needs for healthy sleep. And just like with any sort of mattress shopping, seeing and feeling a mattress in person can make a real difference. Visiting a local store lets you perform these checks yourself, compare different models side-by-side, and ask any questions you have.
Speaking of questions, here are a few more questions we hear from our own crib shoppers:
Are Crib Mattresses All the Same Size / Interchangeable?
One of the most important safety rules is to use the mattress that matches the crib type. We cover this in more depth in our guide to crib mattress types and sizes.
The long and short of it is that standard full-size crib mattresses are only compatible with full-size cribs. This is the only type of crib and mattress combination that has standardized specifications.
Meanwhile, mini cribs, portable cribs and playards do not have standardized dimensions and their mattresses can vary in size based on model and manufacturer. As a result, these special types of cribs should only be used with mattresses specifically designed for the product.
Do not try to make a mattress work by adding blankets, padding, or other materials to fill gaps. If the mattress does not fit correctly, it is not the right mattress for that crib.
Can You Reuse a Crib Mattress?
Some parents may consider reusing a crib mattress for a second child, but that decision deserves careful consideration. While this can be done under certain circumstances (for instance, if the crib mattress is in like new condition, was barely used, etc.), it is honestly not something we recommend.
Please remember that a mattress that has become softer, developed uneven areas, or no longer feels as firm and supportive as it once did is not going to be the best choice. Even if wear is not immediately obvious, an older mattress may not offer the same flat, firm surface that a new baby needs. If there is any doubt about the mattress’s condition, firmness, or cleanliness, we recommend starting fresh.
Do You Need a New Mattress for a Toddler Bed Conversion?
In many cases, no. If the crib converts into a toddler bed, the same crib mattress is often used for the toddler-bed setup.
That said, the mattress should still be in good condition. If it has become worn, sagging, or less supportive over time, it may be worth reevaluating whether it still makes sense to keep using it.
Is a Waterproof Mattress Cover Safe on a Crib Mattress?
A thin, properly fitted waterproof mattress cover can be a practical addition, especially for easier cleanup of night-time accidents. The key is that it should fit snugly and should not create extra padding or a softer sleep surface.
A waterproof cover is not the same thing as adding a thick topper or padded layer. Parents should avoid adding anything that changes the firmness or flatness of the mattress.
More Questions About Cribs, Mattresses & Beyond? We Have Answers.
A safe crib mattress starts with the basics: the right size for the crib, a snug fit, a firm feel, and a flat surface. Those fundamentals matter more than any extra features ever could.
If you are choosing between crib mattresses, the best place to start is by making sure the mattress matches the crib and checking that it passes simple fit and firmness tests. Those steps can help give parents more confidence that the crib is set up safely for sleep.
If you want help comparing cribs and crib mattresses in person, our team at Woodstock Furniture & Mattress Outlet is happy to help you sort through the options and make sure you are choosing a safe fit for your nursery, whether it’s something we have in-store or not. Come see us at any of our North Georgia and Metro Atlanta furniture stores today!
