Crib Mattress Dimensions: What is Best for Baby?

crib mattress dimensions

Are you starting your nursery shopping with cribs in mind? Learn the ins and outs of cribs, crib mattress dimensions, and crib safety here.

One of the most exciting parts of planning and assembling a nursery is selecting a crib.  Finding a crib that accents your nursery decor and theme makes the room feel “complete” and “ready for baby.”  There are a multitude of designs for you to select based on color, shape, crib size, crib mattress dimensions, actual crib dimensions, wood carvings, and ornate details, and more.  Once you have selected a crib style, the baby mattress size will correlate with the crib.  

The basics of crib mattress dimensions

A standard crib mattress size fits snugly within the shape and spacing of the crib. Some cribs are sold as a package with the baby mattress included with your purchase; and there are also cribs sold without a corresponding baby mattress so you may select the one you prefer. Just like adult mattresses, baby mattresses come in a variety of materials. You can select anything from memory foam to natural bamboo threads, to traditional spring mattresses with plastic coverings, and more.  The most important part of choosing a crib is not about what size is a crib mattress, it is about providing a safe sleeping space for your child within your home.  

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Cribs, bassinets, and portable cribs (also known as pack’n’plays) are all viable options for sleeping arrangements for your child.  As you look to select a crib, be sure to create a wish list of features, define and measure your crib mattress dimensions and the space your crib will occupy, and outline a budget. 

Helpful hint: one of the best investments you can make is a good waterproof mattress protector. (Check this one out here) Taking it one step further, having at least two of these waterproof mattress protectors on hand at home allows you to have one on the crib, and one extra to put on in case the current one in use becomes soiled with urine, poop, or vomit. Twin parents may actually want to have four waterproof mattress protectors if your twins are occupying separate beds.  There are waterproof mattress covers for standard crib size, mini cribs, and portable cribs (pack’n’plays.) 

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crib mattress dimensions. pregnant woman looking at put together crib while holding belly

How big is a standard size crib mattress?

The standard crib size is about 28 inches wide by 52 inches long. According to the Consumer Products Safety Commission, crib mattress dimensions should be no more than 6 inches thick and measure at least 27 1/4 inches wide and 51 1/4 inches long.

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Are all crib mattresses standard size?

No, crib mattress size can vary.  There are also mini cribs that are significantly smaller than the standard size crib. Mini crib dimensions are generally around 24 inches wide by 38 inches long.  

Is a crib mattress the same size as a toddler mattress?

Yes, a crib mattress and a toddler bed mattress are interchangeable. In fact, most cribs are manufactured to convert into a toddler bed in later phases of childhood.  Purchasing a quality mattress while your child is an infant will help it last well into their toddler years.  

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crib mattress dimensions A rug, chair and crib with a mattress in a room with a photo hanging above it on the wall

How is a crib mattress supposed to fit?

A crib mattress should fit snugly into the brackets provided with the crib assembly.  Carefully read the assembly instructions as many cribs begin with a higher depth setting when the baby is an infant, and adjust to a lower depth as the baby begins to pull themselves up, or stand.  

Is it safe to put crib mattress on floor inside crib?

It depends on your child’s developmental milestones.  For infants, it would not be safe to put a crib mattress on the floor because of the risk of the child rolling into an area where suffocation could occur.  As the child approaches toddlerhood, it would be acceptable to put the crib mattress on the floor.  Parents often adjust their cribs in this manner when children climb out of their cribs but are still too young to transition into a toddler or adult bed.   Cribs are designed with their own mattress support system – sometimes it is a metal, spring-like “foundation” and other times it has the appearance of a wooden “ladder.”  If your crib mattress dimensions allow your crib to be adjusted to a “floor crib,” you will simply remove the mattress support system and position the mattress on the floor.

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Does a crib need two mattresses?

No, a crib does not need two mattresses. A single crib mattress is sufficient based on crib mattress dimensions.  Having two mattresses could potentially pose a safety risk.  Knowing that standard cribs, mini cribs, and portable cribs, have their own foundation and support system, it eliminates the need to stack two mattresses on top of one another.

What is the best crib mattress?

The best crib mattress is one that fits well, cleans well, and provides proper support for your child.  There is not one style or brand that has been designated as the “best” crib mattress, so doing your research and preparing a list of “must-haves” that fits within your budget is important. 

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crib mattress dimensions crib with bedding and a small white rocking horse against a dark grey textured wall

How thick should bassinet mattress be?

Bassinets are a convenient bedding option for infants and parents alike.  A bassinet mattress or pad should be no more than 1.5 inches thick; anything thicker than that is a suffocation hazard.  

Transitioning a baby from a bassinet or portable crib to a standard crib is a milestone many parents have anxiety over.  When you’ve established a good sleep pattern and routine, a standard crib is a perfectly acceptable sleeping arrangement for your infant.  There are many other sleep tools you can utilize like swaddles, noise machines, humidifiers, pacifiers, fans, and light shows to help your baby sleep safely and soundly. 

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Crib Mattress Dimensions: What is Best for Baby?

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