The Crib Mattress Guide: How to Choose the Right Mattress

Bungle Nursery Cribs · Buying Guide

The Crib Mattress Guide

The mattress is one of the most important pieces inside your baby's crib. Learn what matters most—from firmness and fit to materials, cleaning, sizing, and the features worth considering before you buy.

Start With Safety View Shopping Checklist
01 Firm & flat 02 Proper fit 03 Fitted sheet only 04 Materials that fit your priorities
Before You Buy

Start with the sleep surface.

A beautiful crib is only part of the sleep environment. The mattress underneath your baby should be selected with safety, compatibility, fit, and everyday practicality in mind.

There are plenty of choices—from traditional foam and innerspring mattresses to organic and natural-material options, waterproof covers, breathable designs, and different price points. The goal isn't to find the mattress with the longest feature list. It's to find one that fits your crib correctly and meets the needs that matter most to your family.

01

Firm & Flat

Infant sleep surfaces should be firm, flat, and designed for the crib or sleep product being used.

02

Correct Fit

The mattress should be compatible with your specific crib and fit snugly without dangerous gaps.

03

Simple Sleep Space

For infant sleep, the recommended sleep space contains the mattress and a fitted sheet—nothing else.

04

Choose Your Priorities

Materials, waterproofing, breathability, weight, cleaning, and price can help narrow your choices.

01 — Safety First

The four things you should never compromise on.

Before comparing materials, colors, certifications, or special features, make sure the mattress and sleep environment meet the fundamentals of safe infant sleep.

01

Firm & Flat

The American Academy of Pediatrics recommends a firm, flat sleep surface for infants. A firm surface should not indent when your baby is lying on it.

02

Designed for Your Crib

Choose a mattress designed and labeled for the crib or sleep product you are using. Compatibility matters because poor fit can create dangerous gaps.

03

Fitted Sheet Only

Keep the infant sleep surface bare. CPSC and the AAP recommend using a fitted sheet and keeping blankets, pillows, bumpers, toys, and other loose items out.

04

Check Compatibility

For an aftermarket mattress, look for compatibility information identifying the specific crib or sleep product for which the mattress is intended.

Official safety guidance: The U.S. Consumer Product Safety Commission and American Academy of Pediatrics both emphasize a firm, flat sleep surface and a bare infant sleep environment. Always follow the instructions supplied with your specific crib and mattress.
02 — How to Choose

Once safety is covered, compare what matters to you.

There isn't one mattress feature that every family needs. Use these six questions to narrow the field without getting lost in marketing language.

01

Does It Fit?

Confirm the mattress is intended for your crib and check the dimensions listed by both the crib and mattress manufacturers before purchasing.

02

How Firm Is It?

Firmness is a foundational consideration for infant sleep. Avoid choosing a mattress simply because it feels plush or comfortable to an adult.

03

How Easy Is It to Clean?

Babies create plenty of messes. A removable, washable, waterproof, or easy-clean cover can make everyday care considerably simpler.

04

What Materials Do You Prefer?

Families may prioritize foam, coils, natural materials, organic materials, certifications, or a particular manufacturing approach.

05

How Much Does It Weigh?

A lighter mattress can be easier to lift when changing sheets or cleaning the crib. Weight can be especially useful to consider when comparing otherwise similar options.

06

What Happens After the Purchase?

Review the manufacturer's warranty, return policy, trial period, care instructions, and available customer support before making your final decision.

03 — Size & Fit

The right size isn't a preference. It's part of safety.

Never assume that two mattresses will fit the same crib simply because they look similar. Check the crib's instructions and the mattress manufacturer's compatibility information.

Full-size crib mattresses

For a full-size crib, the CPSC specifies mattress dimensions of at least 27¼ inches wide by 51¼ inches long, with a thickness not exceeding 6 inches. The crib itself has standardized interior dimensions, but the mattress still needs to meet the applicable requirements and fit correctly.

Minimum Mattress Width 27¼ in.
Minimum Mattress Length 51¼ in.
Maximum Thickness 6 in.
Most Important Check Compatibility
Before Checkout

Don't shop by dimensions alone.

Mattress dimensions are only part of the equation. For aftermarket mattresses, CPSC advises consumers to look for specific compatibility statements identifying the crib or play yard models for which the mattress is intended.

  • Check your crib manual. Follow the mattress requirements supplied by the crib manufacturer.
  • Check the mattress label. Look for applicable size and compatibility information.
  • Do not add padding. Supplemental padding should not be used in infant sleep spaces.
04 — Materials

Different materials. Different priorities.

Mattress construction can vary considerably. Rather than treating one material as automatically right for every family, consider how each approach aligns with your priorities.

Traditional Construction

Foam

Foam mattresses can offer a lightweight construction and straightforward design. When comparing foam models, focus on the complete mattress specifications, firmness, cover, certifications, and compatibility rather than foam type alone.

Traditional Construction

Innerspring

Innerspring mattresses use a coil-based support structure. Families comparing these models should consider construction, firmness, weight, cover materials, cleaning features, certifications, and warranty information.

Natural-Material Focus

Organic & Natural Materials

Organic and natural-material mattresses appeal to parents who want to pay particular attention to the materials used in their baby's sleep environment. Look closely at the actual materials and certifications rather than relying on broad marketing terms.

Feature

Breathable Designs

Some mattresses are designed around increased airflow or breathable covers. These features can be part of a family's preference, but a breathable or specialty mattress does not replace the fundamentals of safe infant sleep.

05 — Features

The features that make everyday life easier.

Once you've established that a mattress is appropriate for your crib, these practical features can help you decide between otherwise comparable options.

01

Waterproof Protection

Helpful for protecting the mattress from everyday accidents and making cleanup easier.

02

Washable Cover

A removable, machine-washable cover can simplify routine cleaning when messes happen.

03

Low Weight

A lighter mattress can make sheet changes and cleaning easier for parents and caregivers.

04

Certifications

Independent certifications can provide additional information about materials, emissions, or manufacturing standards when applicable.

05

Warranty & Trial

Review the manufacturer's warranty, return terms, trial period, and exclusions before purchasing.

06 — Cleaning & Care

Choose a mattress you can actually live with.

The nursery looks beautiful before the first diaper leak. Then real life begins. Cleaning features become much more important once you're changing sheets at 2 a.m.

Everyday Practicality

What makes cleanup easier?

Look for care instructions that fit your routine. Depending on the mattress, useful features may include a waterproof surface, removable cover, washable cover, or wipe-clean materials.

  • Check whether the cover can be removed.
  • Follow the manufacturer's washing instructions.
  • Never use cleaning products that the manufacturer does not recommend.
  • Allow components to dry completely according to the manufacturer's directions.
A Small Detail That Matters

Don't improvise the sleep surface.

If you need additional cushioning, padding, or another layer to make a mattress feel more comfortable, stop and check the manufacturer's instructions. Supplemental padding should not be added to infant sleep spaces.

  • Use the mattress as designed.
  • Use the appropriate fitted sheet.
  • Follow the crib and mattress instructions.
07 — Safe Sleep Basics

Keep the sleep space simple.

The mattress itself is only one part of the sleep environment. These basic reminders are worth keeping in mind after the mattress arrives home.

Do

  • ✓ Place baby on their back for sleep.
  • ✓ Use a firm, flat sleep surface.
  • ✓ Use a mattress designed for the crib.
  • ✓ Use a properly fitted sheet.
  • ✓ Check for recalls when appropriate.

Don't

  • × Add pillows or loose blankets.
  • × Add padded crib bumpers.
  • × Add supplemental mattress padding.
  • × Use an incompatible mattress.
  • × Assume a specialty feature replaces safe-sleep fundamentals.
08 — Before You Buy

Your crib mattress shopping checklist.

Save this list and use it when comparing mattresses. If a product checks the important boxes and fits your priorities, you're much closer to making a confident choice.

Check these before checkout.

  • The mattress is intended for my specific crib or sleep product.
  • I confirmed the required dimensions and compatibility information.
  • The mattress provides the firm, flat sleep surface recommended for infants.
  • I understand what the cover is made from and how it should be cleaned.
  • I know whether the cover is waterproof, washable, removable, or wipe-clean.
  • I reviewed any relevant certifications or testing information.
  • I understand the warranty and return or trial policy.
  • The mattress fits my budget without sacrificing the fundamentals.
Questions Parents Ask

Crib mattress questions, answered.

Still comparing options? Start here, then review the manufacturer's product information for the mattress you're considering.

What makes a crib mattress safe for an infant?
A safe infant sleep surface should be firm and flat, and the mattress should be appropriate and compatible with the crib or sleep product being used. The sleep space should remain bare except for a properly fitted sheet. The CPSC and AAP provide detailed safe-sleep guidance.
How do I know if a crib mattress fits correctly?
Start with the crib manufacturer's requirements and the mattress manufacturer's compatibility information. For full-size cribs, CPSC provides dimensional requirements, but compatibility should still be confirmed for the specific crib and mattress combination.
What size is a standard full-size crib mattress?
CPSC requires a full-size crib mattress to be at least 27¼ inches wide and 51¼ inches long, with a thickness not exceeding 6 inches. Always follow the specific requirements supplied with your crib and mattress.
Should I buy an organic crib mattress?
Organic is a materials preference rather than a substitute for safe-sleep fundamentals. If organic or natural materials are important to your family, review exactly which materials are used and look for certifications that apply to the product.
Is a waterproof crib mattress better?
Waterproofing can be a practical feature because it can make cleanup easier and help protect the mattress from everyday messes. It is not, by itself, a measure of whether a mattress is appropriate for infant sleep.
Do breathable crib mattresses make sleep safer?
Some mattresses are designed with breathable materials or covers, but parents should not treat breathability as a replacement for safe-sleep fundamentals. The AAP recommends a firm, flat sleep surface and a bare sleep space.
Can I add a mattress topper to make the crib mattress softer?
No. Supplemental padding should not be added to an infant sleep space. The mattress should be used as designed and should provide the appropriate firm, flat surface.
Does my baby need a special mattress to reduce the risk of SIDS?
Parents should be cautious about products that claim to reduce the risk of SIDS. The AAP notes that special mattresses and specialized sleep surfaces have not been shown to reduce SIDS risk. Focus on established safe-sleep practices instead.
When should I replace a crib mattress?
Follow the manufacturer's instructions and inspect the mattress regularly. Replace a mattress if it is damaged, no longer fits correctly, has been recalled, or otherwise fails to meet the manufacturer's requirements for continued use.
Where can I shop crib mattresses at Bungle Nursery Cribs?
You can explore the Bungle Nursery Cribs crib mattress collection to compare available options. We also carry organic crib mattresses for families specifically looking for organic and natural-material options.
Ready to Choose?

Find the mattress that fits your nursery.

Start with safety and compatibility. Then choose the materials, features, and price point that make the most sense for your family.

Shop Crib Mattresses Explore Organic Mattresses

Important: This guide is intended for general educational purposes and does not replace the instructions provided with your crib or mattress, or guidance from your pediatrician.

Safe-sleep information: U.S. Consumer Product Safety Commission — Safe Sleep · CPSC — Crib Mattresses FAQs · American Academy of Pediatrics — Safe Sleep