When to Lower Crib Mattress Height?

VD October 10 2023

So, you wonder when it is the right time to lower your baby's crib mattress? Or perhaps you have noticed that your little child keeps reaching new milestones, and you are thinking of making some adjustments to their sleeping arrangements.

This step is quite important and can't be skipped. Trust us, adjusting your crib mattress height can be a straightforward yet crucial stage of growing your little loved one.

If you do not do that at the right time, then it might bring discomfort to the baby. So, you definitely should be aware of when you are recommended to lower a crib mattress height. This is what we are going to tell you about right now.

Comprehend safe sleep practices

Comprehend safe sleep practices

Actually, we have something vital to say. Do you know that there are some specifics of when to lower the crib mattress? Yes, you read it right.

It would be nice to highlight some fundamental sleep practices for infants. Basically, these practices are created to decrease the risk of Sudden Infant Death Syndrome and ensure that your baby sleeps soundly and safely:

Crib safety standards

First of all, make sure your crib meets or exceeds certain safety standards. This means that you have to check for recalls or safety updates related to your crib model on a regular basis.

Avoid sleep positioners

It's advisable to avoid using sleep positioners or other devices that could restrict your baby's movement during sleep.

Back to sleep

Place your baby on their back to sleep every time. This position is recommended to reduce the risk of SIDS.

Safe bedding

Keep in mind that the crib should be free of loose bedding, pillows, and stuffed animals that could pose suffocation hazards.

So now we are ready to talk about the key question: when should you lower the crib mattress height?

When to lower your crib mattress

When to lower your crib mattress

The decision to lower your baby's crib mattress should be based on their developmental milestones and growth. Here's a breakdown of when and why you should consider adjusting the crib mattress height:

  1. Newborn Stage

During the initial newborn stage, when your baby is tiny and less mobile, you should use the highest setting for the crib mattress. This elevated position makes it easier for you to lift your baby in and out of the crib, reducing strain on your back.

It's also an ideal height when transitioning your baby from a bassinet to a crib. However, remember that this height is suitable for babies under five months old.

  1. Sitting up

Once your baby starts sitting up unassisted, usually around five to eight months of age, it's time to lower the crib mattress. When babies can sit up, they're on their way to pulling themselves up.

A higher crib mattress setting at this stage can lead to potential falls or accidents as they become more mobile. Lowering the crib ensures their safety as they explore their newfound mobility.

  1. Pulling up

Pulling up marks another significant milestone in your baby's development. When your baby starts pulling up on the sides of the crib, it's essential to lower the mattress to its lowest setting.

At this stage, your baby's muscles are growing and their desire to explore their surroundings is increasing. A higher crib mattress height could lead to falls or climbing attempts, making it crucial to prioritize their safety by adjusting the mattress.

  1. Taller than thirty-five inches

As you know, babies grow rapidly during their first year of life, and some may reach a height of 35 inches or more. When your little one approaches this height, it might be time to consider transitioning them to a toddler bed.

It's important to note that once your baby reaches 36 inches tall, experts recommend moving them out of the crib and into a toddler bed for their safety.

How to lower a crib mattress

How to lower a crib mattres

Now it's the perfect time to go through the simple steps on how to lower your mattress safely:

A) Pick height setting

Decide which height setting you want your crib to be at, taking into account your baby's developmental stage.

B) Remove bedding

Take off the crib sheets and mattress protector to prevent them from getting snagged or torn while adjusting the mattress.

C) Reset

Once you've adjusted the mattress height, refit your mattress protector and sheets onto the lowered mattress.

D) Make adjustments

Carefully remove the screws from the foot of the crib, then lower the mattress to your preferred setting and secure the mattress by reinserting the screws.

Lowering to the floor

In some cases, if your baby is exceptionally active or attempting to climb out of the crib, you might consider lowering the crib mattress to the floor.

Nonetheless, it's necessary to confirm that your crib is designed for this option. Please follow the manufacturer's instructions provided in the crib's manual to lower the mattress properly. Avoid various DIY solutions as they may create gaps that pose suffocation risks.

The role of safe sleep

The role of safe sleep

A good night's sleep is essential for both babies and parents, but it should always come with safety as a top priority. Staying up-to-date on crib safety practices is vital to provide a secure sleep environment for your little one.

Remember to check the American Academy of Pediatrics' suggestions for safe sleep practices regularly. Also, ensure that your crib and crib mattress meet or exceed safety standards.

When it's time to lower the crib mattress height, follow the guidelines we have already discussed based on your baby's unique developmental milestones.


To summarize, the things that were talked about earlier can provide your baby with the best conditions for a restful night's sleep. As your baby grows and reaches new milestones, be prepared to adjust the crib mattress height accordingly.

This step is almost inevitable. We hope that you will easily understand now when it's the perfect time to lower your crib’s mattress height and bring your children more satisfaction.