How to Choose a Mattress for a Child Moving Out of a Crib

Start with why your child is leaving the crib, because your first step may not be a new mattress at all.

A convertible crib's toddler-bed mode takes the crib mattress. If your child climbs out, the AAP's stopgap is the crib mattress on the floor. If you do need a new mattress, set up the room and choose the bed. Then fit the mattress to that bed and judge the feel yourself.

Table of Contents

• When It's Time to Leave the Crib
• Toddler Bed, Twin or Full
• Set Up the Room Before the Bed Arrives
• Rails, Gaps and Mattress Thickness
• Choosing the Feel for a Child Who Can't Describe It
• From Crib to Big-Kid Bed, Step by Step

Start From Why You're Moving

When It's Time to Leave the Crib

Climbing out is the clearest sign. The AAP says that "once your toddler can climb out of their crib, it may be time to transition to a 'big kid' bed."

The AAP's room-safety page also gives you a measurement. It suggests moving your child to another bed at 35 inches (89 cm) tall. It also suggests the move once the crib's side rail is less than three-quarters of their height, about nipple level.

You might be tempted to carry the crib rules forward as a spec for the new bed. But the AAP writes its safe-sleep recommendations for babies up to 1 year of age. Its big-kid-bed advice focuses on climbing, the room and the bedtime routine. It doesn't give a mattress spec.

Toddler Bed, Twin or Full

Pick the bed first, because the mattress follows the bed.

The CPSC describes a toddler bed as one sized to take a full-size crib mattress. It's intended for a child at least 15 months old who weighs no more than 50 lbs.

To judge the cost, count the purchases each path means. Reusing the crib mattress now means one more bed later. A twin or full now may be your only purchase for years.

A bigger bed costs more now, because price reflects size, materials and construction. Weigh that against the room you have and the frame you choose. If you're torn between the two sizes, see how a twin compares with a full. Leaning twin? Here's how to choose a twin mattress for your child.

Set Up the Room Before the Bed Arrives

Get the room ready first. A child who can climb out of a crib can climb other things too.

• Anchor furniture. The CPSC's Anchor It! campaign advises anchoring TVs and top-heavy furniture and installing a new dresser's anti-tip devices right away. It also says to clear toys and other tempting items off the tops.
• Block the climbing routes. The AAP suggests latching or taping drawers shut so they can't be used as steps. It also suggests gates at the bedroom door and the top of the stairs, and says to move furniture and large toys your child could fall against.
• Mind the windows. The AAP says not to place any child's bed near a window and to secure window guards. It notes that the CPSC recommends cordless window coverings if possible.
• Unwrap and discard. The AAP says to remove and destroy all plastic wrapping from a new mattress, because it can suffocate a child.

Rails, Gaps and Mattress Thickness

The mattress has to match the bed and any rail. The CPSC's toddler-bed standard says the upper edge of the guardrail must be at least five inches above the mattress. Cribs that convert into toddler beds must meet the same standard.

• Thickness. A mattress thicker than the bed was made for sits higher against its guardrail. So use the mattress size and thickness that the bed's own instructions give.
• Convertible cribs. The crib's instructions say which mattress toddler-bed mode uses.
• An adult frame. A twin or full on an adult frame raises a different question: the portable bed rail. The CPSC describes these rails as used on the side of an adult bed for children typically age 2 to 5. Its standard says a rail must not create a dangerous gap with the mattress. Its warnings say rails should never be used with children younger than two. Follow the rail's own instructions for which mattress it fits.
• Bunks. A top bunk isn't a first bed. The CPSC says the bunk-bed label warns against placing children under 6 on the upper bunk.

The bed's own
instructionsThicker than the bed
was made for

Choosing the Feel for a Child Who Can't Describe It

Should it be firm like the crib mattress?

The crib rules came with an age limit. The AAP pages cited here set no firmness rule for older children.

That leaves you, the adult, to check construction, edge and fit. Press it, sit on the edge, and lie on it if you'll lie beside your child. Keep in mind that how far it sinks under you isn't how it holds a much lighter child.

Mancini's Sleepworld's comfort guide uses four groups (Extra Firm, Firm, Medium Firm, Soft). Treat them as words for comparing, not as a pick for your child. For questions about your child's sleep space, the AAP suggests talking with their pediatrician.

Can my toddler test it in a store?

Let them bounce. A toddler's quick bounce tells you little, though, so the adults check construction, edge and fit.

At a Mancini's Sleepworld location, one of 50+ locations across Northern California, press the surface with your hand. Sit on the edge where you'd sit for the bedtime story. Then lie down on twin and full options. If you lie beside your child at bedtime, your comfort counts too.

Firmness names belong to each maker. Because Mancini's Sleepworld carries many brands under one roof, you can compare several twins at a similar feel instead of trusting one brand's label.

Will it last through potty training and beyond?

How long a mattress holds up depends on its materials, construction, the base under it and its care. Size doesn't decide it. Ask what the mattress is made of and how it's built. Then set it on the base its maker's instructions call for.

For accidents and spills, a waterproof layer from the mattress protectors under the fitted sheet helps keep the mattress clean. Washable bedding makes night changes quicker.

From Crib to Big-Kid Bed, Step by Step

1. Name your reason. Find your row in the table at the top of the page. It tells you whether you need a mattress now.
2. Check the crib's conversion instructions. If it has a toddler-bed mode, see which mattress that mode uses.
3. Do the room checks. Work through the list in Set Up the Room Before the Bed Arrives before any new bed goes in.
4. Measure the room and choose the bed. Decide between a toddler bed, a twin or a full. Then pick a frame from the beds and bedroom furniture.
5. Shortlist and test in person, with both caregivers if you can. Browse the full mattress lineup first. At the store, bring the bed's mattress size and thickness instructions. Ask a Sleep Specialist to show you twin or full mattresses within that range.
6. Match the mattress to the instructions. Check it against the bed's instructions and against any rail you plan to use.
7. Make up the bed. Unwrap the mattress and get rid of all the plastic. Then add a protector and a fitted sheet.
8. Keep the routine, and watch for warning signs. The AAP suggests keeping the same routine and expecting trips out of bed for several nights, met with calm, brief responses. The AAP lists frequent snoring, breathing problems at night and daytime sleepiness among possible signs of sleep apnea. It says to tell your pediatrician right away if you notice them. There's more in the guide to children's sleep.

Then take the bed's mattress size and thickness instructions to a Mancini's Sleepworld location, and test your shortlist in person.