Basics Sleep

Are Sleep Sacks Safe For Babies? (When To Use, How Many You Need)

As a parent you don’t need anyone to tell you how important sleep is – both for you and your baby!

When your baby is asleep in their crib or bassinet you will want to keep them warm, comfortable and most importantly safe.

Sleep sacks are an ideal choice because they help ensure your baby is the right temperature and provide plenty of freedom to move around, while eliminating the need for loose blankets, which pose a suffocation risk.

But are they safe for newborns?

What TOG rating should you use and how many do you really need?

And should you consider weighted baby sleep sacks?

Let’s take a look.

What Is A Sleep Sack?

A sleep sack (also know as a sleep bag or wearable blanket) is a wearable blanket designed to keep your baby a comfortable temperature during sleep.

They keep your baby’s torso, legs and feet within the sack, even if your baby moves around their crib.

These sacks are normally made from cotton and are safest when sleeveless, which we’ll cover in more detail shortly.

Sleep sacks have zippers and snaps to make it easy to get your baby dressed for bed, and for making diaper changes as easy as possible, especially in a dark room.

Are Sleep Sacks Safe For Babies?

Yes, sleep sacks are perfectly safe for babies, provided the fit is correct.

How Should A Sleep Sack Fit?

When it comes to fit, the most important thing is to ensure the fabric of the sleep sack cannot go over your baby’s head.

So you don’t want it to be too loose around the neck or arm holes.

In addition, you should opt for a sleeveless sack rather than one with sleeves.


Because a sack that covers your baby’s arms may have a lot of excess fabric.

This excess fabric could make it difficult for your baby to move freely, so if your baby becomes trapped on their front, the excess arm fabric could stop them moving freely, increasing the risk of suffocation.

Are Sleep Sacks Safe For Newborns?

Fortunately yes, sleep sacks are as safe as swaddles for newborn babies, provided the fit is correct.

As mentioned, you should ensure the fabric cannot go over your baby’s head, and opt for a sleeveless sack.

Most manufacturers make it easy to find the right fit by providing sizing information based on your baby’s age, weight and height.

Do Sleep Sacks Help Prevent SIDS?

Putting your baby to sleep using loose blankets increases the risk of SIDS – Sudden Infant Death Syndrome.

The advantage of a sleep sack is that it’s a safer alternative to a loose blanket because it eliminates the risk of suffocation.

Do Babies Sleep Better With Sleep Sacks?

The great thing about using a sleep sack is that it helps build a consistent routine.

By dressing your baby in a sack before every nap or every night, your baby will come to associate the bag with sleep and this should help with the transition from awake to going down and from sleeping in your arms to independent sleeping.

smiling woman carrying baby

Are Sleep Sacks Safe For Babies Who Can Roll Over?

Yes, sleep sacks are safe for babies who can roll over.

The correct size sack will allow your baby to move freely without the risk of being trapped or having fabric cover their head.

Again, provided their arms and hips are free to move, there are no issues with using sacks for babies who can roll over.

Do Sleep Sacks Hinder Development?

Some parents may be concerned whether a sleep sack hinders a child’s development.

Provided your baby is dressed in a sack that allows for plenty of hip movement, there are no issues with hindering their development.

Are Weighted Sleep Sacks Safe?

There is conflicting advice about the safety of weighted sleep sacks.

The advantage of these is that is may help a baby sleep better because it recreates the feeling of being “held” and feeling secure.

However, many experts believe weighted sacks may inhibit breathing, especially in younger babies.

It is recommended to never use a sack that weighs more than 10% of your baby’s body weight, but for extra piece of mind you should check with you pediatrician before using a weighted sack.

How Many Sleep Sacks Do I Need?

As a minimum you will need 2 sleep sacks, but many parents find they need 3 to 6 sacks as there are several factors at play, including:

When Should You Stop Using A Sleep Sack?

With all their benefits, you’re probably going to want to use sleep sacks for as long as possible.

But when should you stop using them?

There is no one size fits all as to when to stop using a sleep sack.

Your baby’s size (height and weight) are more important than their age when deciding to transition from a sleep sack to a blanket.

As a general rule, most babies can use them until around the age of 2.

However, some babies continue to use sacks for longer.

If your baby moves around a lot in their bed then you may want to stay with a sleep sack for longer.

This is because unlike a blanket, a sack will stay in place and keep your baby warm however much they move in their crib.

Must Read: The Ultimate Guide To Baby & Toddler Sleep

Tori is mama to 3 year old Isabella and co-founder of Rockinbaby. She has a BSc in Psychology, is a certified yoga teacher and is a working mom. In her free time Tori loves cooking delicious foods and baked treats, entertaining and working out. Learn more about Tori here.

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