Crib Mattress Buying Guide: How To Choose A Mattress For Your Baby

baby sleeping on crib mattress

There are several decisions to make when outfitting your baby’s nursery. And when it comes to choosing a crib mattress, there is a lot to consider — it’s more than just getting the right size and covering it with a cute fitted sheet!

Deciding on a mattress also includes looking out for your baby’s safety, the ease of cleaning the mattress, and so much more. But don’t worry, we’re here to make things crystal clear!

To help you make a great choice, we’ll list several of the most important considerations when choosing a crib mattress, including its size and shape, firmness, materials, breathability, cleaning, and linens.

Table Of Contents

What To Consider When Choosing A Crib Mattress: Safety

The most important thing to consider is safety. You need your crib mattress to fit snugly and be firm; otherwise, it’s unsafe and could contribute to SIDS (Sudden Infant Death Syndrome).

To keep your baby safe while sleeping, let’s talk about the size and shape of their mattress first.

Size And Shape

Expecting mom standing next to crib in zoo themed nursery

Obviously, the crib needs to fit around the crib mattress like a glove. Cribs are sometimes made in shapes like ovals and circles, and if you opt for a shaped crib, it will typically come with the corresponding mattress.

But when it comes to run-of-the-mill rectangular cribs, the two sizes are standard and mini. A standard-sized crib (around 28 inches by 52) uses a standard crib mattress. And a mini crib (24 by 38 inches) uses a mini mattress.

Easy, right? Yes, but you’ll still need to check the fit. While the size of standard crib mattresses is regulated, there is a bit of wiggle room. Meanwhile, the size of mini crib mattresses is not regulated.

Regardless, your job is to test the fit of the mattress in the crib to make sure it’s snug.

A big gap between the mattress and the inside of the crib poses a safety hazard for your little one. How can you tell if the fit is perfect? In general, when the mattress is inside the crib, you should not be able to fit more than two fingers between it and the crib frame.

If the gap is more extensive, your little one can get their head or other body parts trapped between the mattress and the rails. This entrapment can lead to injury or even death.

Your crib’s owner’s manual should list the specific dimensions of the mattress it takes. If it doesn’t, you’ll need to take your own measurements to ensure you buy the correct size.

However, you don’t want to use just any mattress that fits. You also need to consider whether it’s soft or firm.


big sister looking over her new sibling that laying in crib on crib mattress

Sleeping on a soft, fluffy surface is a major safety hazard for your little one. This means your baby should never sleep on your bed or the couch, and you should choose a firm crib mattress.

Sleeping on a firm mattress might not sound appealing to you. But just remember that for babies, it is the safest way for them to snooze.

As part of safe sleep recommendations, the American Academy of Pediatrics advises putting babies to sleep on a firm surface. But keep in mind that a firm mattress doesn’t have to mean a rock-hard and uncomfortable mattress.

It should be firm but not hard. You can tell a mattress is firm enough if it immediately bounces back when you push your hand down into it. If it leaves an indentation, it’s too soft.

Here are two primary reasons why your baby needs to sleep on a firm surface:

  • Babies lack the head control to avoid sinking into a too-soft mattress. If the mattress conforms to their head, it creates a low spot that can trap them and potentially cause suffocation.
  • Their bones and muscles are still developing, and the resistance provided by a firm mattress helps them get stronger.
  • In addition, plenty of studies have shown that babies are safer when their crib mattress is firm. But as a parent, you know that your baby sleeps better when comfortable, so you want to find a mattress that balances firmness and comfort.

Some parents try to make their baby’s bed cozier by adding a foam topper. But this is a bad idea. Since the topper isn’t secured to the rest of the mattress, your little one could quickly work it up in one corner and get their head trapped in the gap.

In addition, remember that babies are curious and use their hands and mouths to explore the world. If they get a foam topper in their mouth, they could accidentally bite off a chunk of it and choke.

Don’t use any additional mattress toppers in your baby’s crib to avoid this possibility. Instead, look for the most comfortable mattress you can that’s still firm.

That brings us to our next point to consider: the materials that your crib mattress is made of.


Newton Baby crib mattress

The inside of a crib mattress — what it’s made of — affects comfort, which we will discuss first, as well as the toxicity of the mattress.


Again, for the safest sleep, your baby’s mattress should be firm. But to help them sleep soundly all night, of course it should also be comfortable!

When it comes to comfort for your sweet baby, we love the Newton Baby Crib Mattress. Unlike traditional mattresses — which are often hard, wrapped in plastic, and made with springs, foam, and latex — ours is comfortable and designed for better sleep.

What makes the Newton Baby Crib Mattress different? It’s mostly air!

This mattress is made with a Wovenaire® Core, which is composed of 90% air and 10% material used to make yogurt cups. This provides the comfort of foam and latex without any of the drawbacks, like toxic chemicals, or allergens.

This Wovenaire® Core is then covered with a soft, quilted, 3-D space cover.


Some crib mattresses release volatile organic compounds (VOCs) and other chemicals into the air through a process called off-gassing.

All sorts of objects in your home can off-gas, and sometimes you notice the odor. But not all chemicals have a scent when they off-gas.

Whether you can smell them or not, these airborne chemicals are no good! They can cause respiratory irritation, nervous-system damage, endocrine disruption, and possibly even cancer.

So what’s a parent to do? You’ll want to find a mattress that’s made without materials like polyurethane foam, flame retardant chemicals, and vinyl.

But we’ll let you in on the best way to make sure your baby’s crib mattress is non-toxic. Simply choose a mattress that’s Greenguard Gold Certified.

This certification program tests the chemical emission of a mattress and offers two levels of certification: the Greenguard Certification and the Greenguard Gold Certification, which has some of the most rigorous standards in the world. That’s what you want for your little one.

Here at Newton Baby, our Crib Mattress is Greenguard Gold Certified, but it is not the only product that boasts that label! Our crib mattress covers and mattress pads have also been independently tested and certified.

Organic Crib Mattresses

If you’re wondering about organic crib mattresses and where they come into play in all of this, the quick explanation is that an organic mattress is not always a sure bet.

First of all, even though a product is marketed as “organic,” that doesn’t necessarily mean ALL of its materials are organic. For example, often organic fibers are mixed with chemicals during production. And flame retardants are sometimes added as well, which contributes to the toxicity.

Secondly, an organic mattress may check some of the boxes of what you’re looking for in a crib mattress, but it may not check other important boxes, like breathability. That brings us to our next point.


baby laying on top of Newton Baby crib mattress

Another thing to take into account when deciding on a mattress is its breathability. What are the advantages of a breathable mattress?

Around four to six months of age, your baby will probably learn how to roll over all by themselves, although they could take you by surprise and make the flip earlier!

If your baby rolls onto their stomach in the middle of the night, a breathable mattress allows them to breathe straight through it and helps to reduce the risk of suffocation. That is no small advantage! And it provides a lot of peace of mind for you, too.

The other plus of a breathable mattress is that it provides airflow under your baby while they snooze, meaning no more sweaty backs.

Keep in mind that the Newton Baby Crib Mattress is composed of mostly air — 90% air by volume! That makes it completely breathe-through.

And the mattress cover is made with two layers of Breathe-Thru spacer fabric, quilted together in an attractive cloud pattern to create soft pillows of air.

You can even top it off with our Waterproof Crib Mattress Pad, which is 100% breathable but also 100% waterproof to protect your mattress from leaks, moisture, and mold.

Speaking of which, let’s move onto a consideration that every parent wants to take into account: the cleaning of your crib mattress.

Other Considerations When Buying A Crib Mattress

Hands down, you want a safe crib mattress. The good news is that most of the models on the market today meet government safety standards.

But there are other features to consider, such as how easy the mattress is to keep clean and hygienic, whether or not you need a waterproof mattress, and how much you’ll have to pay. Let’s look at those factors now.


Mom taking cover off crib mattress to clean

Your little one might be an angel, but they will also occasionally grace their mattress with spit-up, nighttime blowouts, and all the rest. Being able to quickly and effectively clean your mattress is important.

Cleaning a traditional mattress involves a cumbersome process of vacuuming, scrubbing, and spraying. On the other hand, the Newton Baby Crib Mattress is the only one that’s washable from cover to core. You can say bye-bye to mold, bacteria, and allergens!

How is it done? The mattress cover can be unzipped, removed, washed in the washer, and dried on low heat.

To wash the Wovenaire core, place it in the shower or tub. Spot-clean as needed with cool water and a mild detergent or vinegar. Then simply shake it out and lay it on its side to dry.

Voila! That’s all there is to it.

Waterproof Or Not

As mentioned earlier, babies are pretty messy. Your mattress will get covered in gross body fluids at some point. When that happens, a waterproof crib mattress can help make middle-of-the-night bedding changes easier.

If you don’t want a waterproof mattress, consider picking up an extra mattress cover so you always have one ready to go after an accident.


When you’re trying to buy everything you need for your baby, you might see dollar signs flashing before your eyes. Sometimes, your budget dictates the type of mattress you can purchase. In that case, get the best mattress that you can afford.

To help save money, consider getting a slightly thinner mattress. For example, our Essential Crib Mattress will save you about $50 compared to the original. This mattress is four inches thick instead of 5.5 inches. But it’s still made from the same breathable materials.

When thinking about the cost, it may help to remember that crib mattresses are designed to last a long time. Your baby should transition into a toddler bed with the same mattress. They won’t need another one until they move to a twin-sized bed in a few years.

This investment lasts a while. When you break it down into a cost per month or year, a quality mattress seems much more affordable than one you have to replace often because of wear and tear.


Newborn baby holding onto dads finger

The final step to choosing a crib mattress is choosing the linens that will go with it. And by “linens” we are simply referring to the fitted sheet because your baby shouldn’t sleep with anything else.

To reduce the risk of suffocation, the American Academy of Pediatrics recommends foregoing any other bedding or soft objects in your baby’s crib. This means no top sheet, no blanket, no crib bumpers, no stuffed animals, and no baby pillows. You get the idea.

As for the fitted sheet, look for one that is not only cute (and matches your nursery decor!) but is also easy to wash, breathable, hypoallergenic, and comfy for your baby.

We recommend the Newton Baby Breathable, Organic Cotton Sheet. It comes in both standard and mini sizes and is made with all-around elastic to guarantee a safe, snug fit for any crib mattress.

Plus, the pre-shrunk, organic muslin cotton is breathable, organic, hypoallergenic, and machine washable for the most hygienic sleep surface possible.

If you plan to swaddle your newborn, look for a high-quality organic cotton swaddle blanket. This can keep your baby at the perfect temperature all night long. A sleep sack is another option if your baby is too big to swaddle.

Common Questions About Crib Mattresses

crib mattress in a mint green crib

While we covered a lot about buying a crib mattress, you may still wonder about some things we didn’t address. To help you make a final buying decision, let’s look at a few common questions parents have.

Can I Buy A Used Crib Mattress?

Maybe you found a great deal on a used crib mattress on Craigslist. Or maybe your sister’s kid recently moved to a big girl bed, and they offer you the hand-me-down.

Whatever the case, proceed with caution when considering a used mattress. You see, your baby will spend a lot of time on it. And there could be damage, even if everything looks fine at the surface level.

For that reason, a new mattress is your best choice. You can rest assured that it will be clean and adhere to the safety guidelines developed by the Consumer Product Safety Commission.

If you decide to take your chances with a used one, look it over carefully before taking it home. Make sure you don’t see any signs of bedbugs. Or discolored patches that could indicate mold. Even small holes or loose threads could cause problems, as these tend to worsen over time.

Sometimes, you’ll find a used mattress that’s in great shape. In that case, take some measurements. If the mattress doesn’t fit in your crib, it’s unsafe. Remember, you need an exact fit, not one that’s close. Never try to fill in the gaps with foam or rolled-up blankets.

Can I Save A Crib Mattress For My Next Kid?

As mentioned above, purchasing a used crib mattress isn’t recommended. But what about hanging onto your mattress for a future baby? Is that OK?

Only if it’s still in good condition. You’ll also need to store it properly so it’s ready for action when your new baby arrives.

Here are some tips for safely saving it between kids:

  • Give the mattress a good cleaning before storing
  • Let it dry completely
  • Examine the mattress for soft spots
  • Check the edges to make sure the seams are still in place
  • Store it in a safe, dry place where mice and other pests can’t get into it
  • Ensure it hasn’t expired (the expected lifespan is usually 5 years)

And of course, once you pull the mattress out for use with your next little one, take time to check it over closely. If you notice any problems, say goodbye to this mattress and get a new one.

How Thick Of A Crib Mattress Does My Baby Need?

Federal guidelines state that a crib mattress should be no thicker than six inches. Most mattresses on the market are between four and six inches.

Mattress in this range will be good for your baby. It might not hold up to everyday use if it's any thinner.

When Should I Buy A Crib Mattress?

Pregnant woman in nursery

At what point in your pregnancy should you buy a crib mattress? Well, that depends on your plans. If your baby starts in a Bassinet & Bedside Sleeper, you’ll have more time.

In that case, plan on having the crib and crib mattress in place when your little one is four months old. That way, when they outgrow their smaller bed, their next bed is ready to go

But if you plan to start your baby in a crib, buy it and the mattress in your second trimester so you can set up the nursery before your little one joins you.

Should I Get A Two-Stage Crib Mattress?

Some companies design mattresses for use with both babies and toddlers. These two-stage options have a soft side and a firm side.

When your baby is little, you’ll have them sleep on the firm side for their safety. But once they reach their first birthday and have met certain developmental milestones, you can flip the mattress over.

This allows your toddler to sleep on a slightly softer mattress that they might find more comfortable during this season of life.

However, there’s a significant downside to buying a two-stage mattress. If you accidentally flip the mattress too soon or use the wrong side, your baby has a higher risk of suffocation. It’s essential to read the labels carefully and ensure the right side is up.

In addition, since these mattresses are designed to last longer, they tend to cost more. Especially if you want to get one that doesn’t contain toxic chemicals.

When Should I Replace A Crib Mattress?

If you take good care of your little one’s crib mattress, it should last for about five years. However, sometimes life happens and you’ll need a new one sooner.

Here are some signs that it’s time to invest in a new one:

  • Indentations
  • Holes
  • Stains from liquid soaking in
  • Loose threads

To keep your mattress in good shape, wash it regularly and clean up spills or accidents before they soak in.

Additionally, you’ll want to keep your crib out of direct sunlight. The rays from the sun can damage the integrity and cause the mattress to break down sooner.

The Best Mattress For Your Precious Baby

Mom kissing baby before laying them down onto crib mattress

There might be a lot of decisions to make when designing and furnishing your baby’s nursery, but with this crib mattress buying guide, choosing a good mattress for your baby doesn’t have to be difficult!

When picking a crib mattress, take into account the size and shape, firmness, materials, breathability, and how easy it will be to clean. For a breathable and washable mattress, choose the Newton Baby Crib Mattress and outfit it with a Breathable, Organic Cotton Sheet.

Before you know it, your little one will be snoozing away on a comfy and safe mattress that was chosen just for them!

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