How to Buy a Crib Mattress for Your Nursery

Shot of a modern baby room with crib
LSOphoto / Getty Images

Shopping for a safe, comfortable mattress for your baby-to-be can be tricky because there are so many. Crib mattresses are not just mini adult mattresses. Take a look at sizes, firmness levels, fabrication materials, and some other factors that come into play when thinking about preserving your baby's safety while they sleep. So, before you hit the bedding aisle at your local baby mega-store or go shopping online, review this comprehensive buying guide and these helpful buying tips to help you make the best decision.

Before Buying a New Crib Mattress

A matter that remains inconclusive is the safety of reusing a secondhand crib mattress passed on from a friend or one of your other children. Regulating bodies in the U.S. haven't said anything about using a previously used mattress, but some mattress companies and sleep sites suggest it's safest to get a new mattress for each child. They point to reports by the Consumer Product Safety Commission (CSPC) enumerating the causes of infant safety hazards: loss of mattress firmness, wrong-sized mattress for the crib, protruding springs or coils, and unraveling stitching.

Also, previously soiled or used mattresses may appear clean but may harbor dust, dust mites, bacteria, mold, mildew, or bed bugs.

The rule of thumb is to give the mattress a thorough visual inspection and check for firmness.  "A crib mattress must be sufficiently firm to prevent a child's nose and mouth from being obstructed by a mattress that is too soft and pillow-like," according to the CSPC.

Look closely at the crib mattress surface and check for depressions in the mattress that make it uneven. A sign that the mattress is too soft is if you press your hand on it, and it doesn't bounce back immediately.

Warning

Crib mattresses made of memory foam are considered a hazard. According to the Consumer Product Safety Commission, "Soft mattresses, including those made from memory foam, could create a pocket (or indentation) and increase the chance of rebreathing or suffocation if the infant is placed in or rolls over to the prone position.”

Buying Considerations for a Crib Mattress

Space

If you have a nursery, a shared children's room, or the crib will be in your bedroom; your available space will dictate the size of your crib and its mattress. When it comes to room space, the two most common options you have are standard crib mattress and mini crib mattress. The option of two crib sizes is game-changing, mainly if you have limited space in your home.

Material

Crib mattresses are generally made of two core materials: foam and innerspring, and they come in different densities, thicknesses, and coil counts. Most foam mattresses are polyurethane, although some companies following the green trend use soybean or other plant oils. Specialty mattress companies have also developed entirely organic alternatives to foam and innerspring, such as mattresses made of wool, cotton, rubber, and coconut fiber.

Many researchers and medical professionals assert that chemicals left over from the manufacturing process or volatile organic compounds (VOCs) of many everyday household items can aggravate medical conditions and even cause new and potentially dangerous health problems. So, if you're hoping to create a chemical-free environment for your child, an organic mattress may be a good starting point.

Size

The legal size for a crib mattress set by the CSPC is 27.25 inches by 51.25 inches, with a thickness not exceeding 6 inches. Although crib manufacturers build their cribs to the standard, sometimes you can find variations, and you must ensure there is no more than a 1-inch gap between the mattress and the sides of the crib. One inch is the equivalent of two fingers.

Non-standard crib mattresses—like mini cribs and foldable play yards—can vary in size and must be sold with the mattress included. Although most mini cribs come in a standard size, mini-crib mattresses measure 24 inches wide and 38 inches long. It's not uncommon for parents to buy mattress upgrades for their mini cribs; some mini cribs may only come with a flimsy mattress pad.

Features

When selecting a baby crib mattress, the features are seemingly endless, but several options seem to be the most desirable: two-sided mattresses, breathability, waterproof, and safety-rated.

  • Two-stage mattresses: If you're planning to convert your baby's crib to a toddler bed, you could consider getting a dual-firmness, two-stage convertible mattress, also called a flippable or two-sided mattress. These mattresses are extra firm on the infant side, and then for the toddler side (after 12 months), you flip it for a somewhat softer mattress.
  • Breathability: Mattress vents allow for breathability and increased airflow. These mattresses make it easier for moisture to escape, preventing mold, mildew, and odor. When choosing your mattress, look for small, reinforced holes along the sides. The more ventilation holes, the better.
  • Waterproofing: Waterproof mattresses keep bodily fluids and germs off of the mattress. In theory, this feature sounds good, but vinyl or plastic coating or covering on a mattress may affect breathability. A good alternative is a separate, waterproof mattress cover or pad placed on top of the mattress and under the mattress sheet to protect the mattress.
  • Safety ratings: Safety ratings and certification hold a lot of weight in this crib mattress arena. All crib mattresses sold in the United States must meet specific safety standards set forth by the CPSC and the American Society for Testing and Materials. But, independent certification can provide peace of mind, especially if you plan on shelling out a couple of hundred dollars extra for an organic mattress. (All organic mattresses are certified using the Global Organic Textile Standards, but a label boasting an organic certification does not necessarily mean the item is entirely organic.) Look for mattresses marked "100% organic" certified by an independent interest group, such as the Environmental Working Group.

Types of Crib Mattresses

Foam

Most foam mattresses are high-density polyurethane foam. They’re lightweight and durable. Some companies make their foam with plant oils for an eco-friendly or more natural approach. Another company has an "air core," more breathable foam for babies certified by CertiPUR-US and Greenguard gold-rated.

Foam mattresses are usually available in various thicknesses, where the thickness of most models goes up to 6 inches. The heavier, denser foams are generally higher quality and more durable.

Innerspring

Innerspring mattresses are defined by having steel coils inside that make these mattresses more resilient and sturdy. Foam can get compressed and degrade quickly over time. With spring mattresses, mattress construction varies by coil count, the gauge or thickness of the coil, the insulator pad, cushioning layer, and cover. Border rods are a must-have since they provide strong edge support. These supports are essential for when your baby stands or walks along the edge.

Higher coil counts add to the price and weight of the mattress. The springs can bring the weight of the mattress up to 15 to 30 pounds; meanwhile, foam mattresses top out at no more than 15 pounds.

The insulator pad protects the mattress from the coil sticking out. It's usually constructed of sheets of cloth fiber, coconut fiber, or felt material. Cushioning material can be made of polyester, cotton, and foam. Covers typically come in two types: fabric or vinyl. Vinyl resists tears, punctures, stains, and leaks, but you sacrifice breathability unless the mattress has ventilation holes or a unique breathability feature.

Organic Alternatives

  • Cotton: A cotton mattress is waterproof and made with organic cotton, innerspring, and a non-GMO sugar cane-derived polyethylene waterproof cover. It is made without harmful chemicals and contains no latex, soy, GMOs, vinyl/PVC, phthalates, formaldehyde, flame retardants, polyurethane foam, or perfluorinated compounds (PFCs).
  • Wool: A wool mattress is pricey but entirely natural, 100% VOC-free, breathable, regulates temperature, controls odors, antimicrobial, and ecofriendly (although not vegan).
  • Rubber: Latex or natural rubber mattresses are renewable and recyclable since they are constructed from the latex sap from rubber trees. One rubber tree produces sap for up to 30 years, making a firm, bouncy, and durable material. It's not as biodegradable as cotton or fibers, but it will eventually biodegrade without releasing toxins into the environment. It is naturally antimicrobial, resists mildew, doesn't harbor dust mites, and is easy to clean with soapy water.
  • Coconut fiber: The fibers from coconut husks can be combined with natural latex to construct an organic, breathable mattress.

Mini-Crib

Mini crib dimensions are usually 24 by 38 inches, but they don't have to be that size since they are not regulated like full-size crib mattresses. Like full-size crib mattresses, mini mattresses come in flippable, two-sided mattresses for infants and toddlers, waterproof, foam, innerspring, and organic alternatives. For your child's safety, you must follow the same two-finger rule for checking the space between the mattress and the crib's sides.

Cost

A quality mattress should see your little one into their "big bed" days and beyond without issue. According to the Consumer Product Safety Commission, the average cost of a crib mattress available for sale in the United States is $150.

You can find crib mattresses starting at $30, but the price quickly mounts as you add features or organic options. Expect to pay between $90 and $200 to get a decent quality mattress. The higher the price, the firmer the mattress, and the better the quality. Low-priced models might be too soft and flimsy.

How to Choose a Crib Mattress

You can find more than 100 options for crib mattresses, and the number of styles continues to rise. The challenge is finding something that serves your needs, fits your space, and falls within your budget. To start figuring out what might work for you, ask yourself these questions:

Is It Necessary to Have a Waterproof Mattress?

Waterproof mattresses are a wonderful invention, but most will impact the breathability of the mattress. Accidents like diaper blowouts, potty training accidents, spit-up, and vomit are likely occurrences. Still, you don't need to have a waterproof mattress as long as you have a waterproof barrier—like a waterproof mattress pad or cover.

Are Dual-Sided Mattresses Worth It?

If you get a flippable, two-sided mattress with an infant and toddler side, they are a versatile option if you plan to transition your little one to a toddler bed. If you intend to go straight to a twin bed or larger bed from the crib, you might not find any value in spending extra for the dual-sided feature.

Can I Reuse a Mattress From a Sibling?

If you plan on saving your child's mattress for use by a potential sibling, be sure to keep it clean and dry while in use and store it in a safe place. Before using it, ensure that the mattress is in good condition and that the center and edges have remained firm and retained their shape.

Foam vs. Innerspring

The vast majority of your crib choices will be foam or innerspring. The structure of foam mattresses is not as complex as the coil mattress’s structure but is equally effective in providing firmness and sufficient support to your child.

Foam mattresses tend to be less expensive, are lighter and easier for changing sheets, and have less spring, so they are less likely to be used for jumping up and down. Their downsides are that the cheaper varieties usually don't last as long as less expensive spring mattresses and may have a factory smell. They can get sunken in over time, and their edges don't hold up as well as spring mattresses.

Warning

Over time, the surface of a once-firm crib mattress can become soft and uneven, putting your little one at risk.

Where to Shop

A crib mattress can get pricey, and it's understandable if some parents-to-be want to see what they're getting before they buy. Many people prefer to see their options firsthand to make sure they like the feel and look. Others do not have the time or prefer online shopping. Online options allow you to order for delivery sight unseen.

Buying In-Store

The most significant benefit of buying in-store is seeing what you're buying. The biggest downside is you have fewer options when shopping in the store. Most shops only carry a handful of mattresses—although they're usually the most popular selections. Before you go to the store, do some basic research online to see which mattresses are in your price range and have the features you like. When you get to the store, zero in on those mattresses to look at them, feel them, flip them over. Notice the heft and think about how you will need to reach down into a crib and frequently change the sheets.

Take a close look at the mattress stitching. It shouldn't have any loose threads. Make sure the construction looks solid. It should feel firm. When you press your hand into the mattress, it should instantly bounce back with no visible signs of an indentation where your hand pressed down. Also, take the time to read the label on the mattress. Manufacturers are required to disclose what a mattress is made of.

Buying Online

What you should care about when buying online is the return policy. If your mattress arrives and does not fit the crib properly, the mattress needs to be returned. Also, if its quality or firmness is less than acceptable, you need assurance that you can return it and not incur additional costs. If you can't get a return guarantee, go to a store instead to do a proper check of dimensions and firmness before buying it.

One thing that should not hold too much sway when deciding on a mattress is its warranty. Warranties don't mean all that much since the child will use them for such a short time. So don't pay for an extended warranty or a warranty that comes with the mattress that brings up the cost of the mattress.

Where to Buy a Crib Mattress

Most brick-and-mortar stores that specialize in baby products or have baby departments will also carry crib mattresses, and they likely carry a more extensive selection online. Mattress stores may also carry crib mattresses. As with almost every item, you can find crib mattresses on Amazon and other online retailers. You have plenty of options for buying a crib mattress. The key is to find that perfect balance of function, quality, and price.

FAQ
  • What type of mattress is best for babies?

    The safest mattresses for infants are firm and well-fitting to the crib. The American Academy of Pediatrics recommends against memory foam mattresses or mattress toppers. Also, make sure the mattress does not leave an indentation when your hand presses down on it and that no coils aren't poking through.

  • How thick should a crib mattress be?

    According to the Consumer Products Safety Commission, a crib mattress should not exceed 6 inches. Most spring mattresses are between 5 and 6 inches thick, while foam mattresses can vary between 4 to 6 inches.

  • When can you flip a two-stage mattress?

    In most cases, you can flip a two-sided mattress from the infant side to the toddler side once the child reaches their first birthday. However, since not all babies mature at the same rate, it is always best to check with the pediatrician first.

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Safety Standard for Crib Mattresses. Consumer Product Safety Commission.

  2. Crib Mattresses Emit High Rates of Potentially Harmful Chemicals, Cockrell School Engineers Find. The University of Texas at Austin/Cockrell School of Engineering.

  3. Non-Full-Size Baby Cribs Business Guidance & Small Entity Compliance Guide. Consumer Product Safety Commission.