Avent Nipple Sizes: Which Should You Choose?

Does your baby cry, spill food, get upset or is overfed after a bottle feeding session? You could be using the wrong nipple size. No two nipple sizes are the same. Some are slower while others are faster. Your baby will need a nipple change as they grow because they will need more food. A slower nipple may not work all the time.

image of avent nipples

Luckily, Avent has six different nipple sizes available. Keep reading to know how to choose the right Avent nipple size for your baby.

AVENT nipple size chart 

Do you need a quick visual guide to Avent nipples? Here’s one:

Avent First Flow NippleAvent Newborn Flow NippleAvent Slow Flow NippleAvent Medium Flow NippleAvent Variable Flow NippleAvent Fast Flow Nipple
Baby’s age 0 months0+ months1+ months3+ months3+ months6+ months
RecommendationBest for newborn and preemiesBest for newborns and breastfed babies of every ageBest for newborns and breastfed babies of every ageBest for 3 months old babies and aboveCan be adjusted to dispense thicker liquidsBest for 6 months old babies and above

Why you shouldn’t use one nipple size 

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Using the wrong size of nipples can make it difficult for your baby to get the right amount of food they need at once. Babies need more food as they grow. Hence, their stomach enlarges, and their ability to swallow also increases to help them eat more within a limited period. 

This is why your baby will become frustrated and impatient if at six months, you feed them with the size of nipple you used when they were newborns. The flow rate will be too slow for them because the newborn nipple opening is small.

On the other hand, using a nipple with an excessive fast flow rate can give your baby more food than they can manage. 

Change to a nipple size with an adequate flow rate to give your baby just enough. Remember that the flow rate of some nipples may not be very suitable for your baby. 

There are no die-hard rules for choosing nipple sizes. The key is knowing what your baby is comfortable with. But knowing the different sizes available and their features will help you choose the most suitable nipple size for your baby.

Types of AVENT nipple sizes

There are six types of avent nipple sizes with different flow rates. they are

  1. Philips Avent Natural First flow nipples
Photo of Natural First flow Avent nipple

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The first flow nipples have a small hole for delivering milk at a slower and more comfortable flow rate for babies. The flow rate is suitable for premies and newborns. 

The wide breast-shaped nipple has unique comfort petals and flexible spiral tips to make it easy for your baby to latch on. Younger babies will not have a problem combining this bottle feeding with breastfeeding.

The silicone material used for making this nipple is durable and ultra soft. It is also BPA free, colorless, and flavorless. They are safe for treatment in Avent steam sterilizer. You can also boil them for five minutes or wash in a dishwasher.


  • The soft silicone material gives the feeling of the natural breast 
  • Babies find it easy to latch on this nipple because of the wide breast shape
  • The nipples won’t collapse during feeding because of the flexible spiral design
  • It is dishwasher safe and BPA free 
  • It is compatible with all of Philip Avent natural bottles


  • The size may be too big for some babies
  1. Philips Avent natural newborn flow nipple
Photo of Natural Newborn First flow Avent nipple

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The size of this nipple is recommended for kids 0 -3+ months. It is a classic nipple and also uses ultra-soft silicone to give the natural feel of a mother’s breast.

The manufacturers included an anti-colic valve to this nipple size to create a vacuum in the bottle and prevent air from getting into your baby’s stomach. Since the bottle has a single hole for the baby to feed through. It regulates the amount of milk they get.

To avoid nipple confusion, this baby’s nipples have a very slow flow when the baby does not apply suction. The flow increases as the baby sucks. We love it because it is also made from BPA and phthalate-free silicones which do not contain chemical odor or taste.


  • It is the best fit for Avent classic+ bottles
  • It emulates natural breastfeeding by allowing your baby to control the amount of milk flow they get 
  • The silicone material used for it is ultra soft, colorless, and odorless 
  • The anti-colic valve reduces fussing and discomfort for baby
  • You can sanitize it in a steam sterilizer, dishwasher, or by boiling


  • It may not fit your baby bottle properly
  1. Philips Avent Natural slow-flow nipples
Photo of Natural slow-flow Avent nipple

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You will love this nipple if you want to combine breastfeeding and bottle feeding. It has a wide shape that makes it similar to a mother’s breast.  It is recommended for kids between one and three months, newborns, and babies of every age. 

It is soft and durable and encourages the baby to latch on naturally. The comfort petals increase flexibility and keep the nipples from collapsing when the child feeds this slow-flow nipple. 

Avent has an anti-colic valve that creates a vacuum in the bottle and prevents the baby from sucking air into their stomach. Babies find this nipple very comfortable.

It is made from BPA and phthalate-free silicone material that is odorless. This nipple is fit for sterilizing in a steam sterilizer, dishwasher, or by boiling.


  • The wide shape mimics mother’s breast and prevents nipple confusion
  • The anti-colic valve prevents air from entering the child’s stomach
  •  It is dishwasher safe 
  • The nipples don’t collapse while your baby is feeding because of the comfort petals that makes them flexible
  • It uses soft, durable, odorless, flavorless, and BPA-free silicone


  • You can only use it with Philips natural bottle
  1. Philip Avent natural medium flow nipple
Photo of Natural Newborn Medium flow Avent nipple

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Babies between three and six months or older can use the Philips Avent natural medium flow nipples. The construction is very similar to the first flow, only that it is designed to fit grown babies. 

It still uses durable, soft, and flexible BPA-free silicone and a wide base with a spiral level design to offer comfort when breastfeeding. Also, it uses an Airflex vent technology to keep air from entering the child’s stomach. 

The only difference between this nipple and the first flow nipples is that the hole on top encourages faster liquid flow compared to the slow flow Avent nipples. 

You can use this nipple with most Philips Avent natural bottles.


  • Latch-on is easy because of the wide breast-shaped nipples 
  • It has an Airflex vent technology that prevents air from getting into your baby’s stomach
  • Is made from an ultra-soft silicone structure which gives the same feeling as the human breast 
  • Nipples don’t collapse when feeding because of the flexible spiral design


  • This nipple may flow too fast for some babies
  1. Philips Avent natural fast-flow nipples
Photo of Natural Fast-flow Avent nipple

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The fast flow design nipples from Philips Avent is recommended for kids not less than  6 months old.  Kids of this age can take in more food than newborns, and the fast flow will not disturb them.

This nipple uses soft silicone materials which are also very durable. This material has no flavor or odor, and is BPA-free. The wide shape makes it similar to a mother’s breast, and the comfort petals and flexible spiral structure prevent collapse when feeding.

Like the medium flow nipples, the fast flow nipples also have an Airflex vent technology that prevents air from getting into your baby’s stomach to cause discomfort.

 The best part is that the fast-flow nipples fit most Philip Avent bottles.


  • It has an Airflex vent technology to reduce air trapping in the baby’s stomach 
  • It is safe to sterilize in a dishwasher 
  • The wide breast-shaped nipples allow babies to enjoy bottle and breastfeeding
  • It still uses soft high-quality silicone that is odorless, flavorless, and BPA-free.


  • This nipple may leak if you use it with a non-compatible bottle
  1. Philips Avent Natural variable flow nipple
Photo of Natural Variable flow Avent nipple

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You can use the variable flow nipples when your baby is four months old, up till six months or more. The good thing about this piece is that you can adjust the flow to suit your baby because of the slot holes.

There are three slot holes on this nipple and they are marked with I, II, and III in order of increasing flow speed. Set the speed you need before putting the bottle in your baby’s mouth.

It also uses ultra soft silicone materials which are free from BPA, flavor, and odor. You can safely sterilize it in the dishwasher. 

This Philip Avent variable flow nipple has an anti-colic valve that prevents air from getting trapped in your baby’s intestines. The flexible spiral tip and comfort petals make it soft and easy to latch on.


  • The difference slot holes allow you to adjust the flow rate between slow, medium, and fast
  • Your baby can breastfeed and bottle feed without nipple confusion because of the soft and wide breast shape 
  • It also has an anti-colic valve that reduces air trap in the intestine and discomfort


  • It is not a good fit for younger newborns

Wondering if Avent nipples are the best for your baby? Read reviews from real moms.

Gagandeep loved it

Gagandeep Kaur is a yoga instructor at Yogic-experience.com. She said:

“Although I exclusively breastfeed my newborn, I do occasionally give him a bottle when we are out. I have been using Avent Nipple, and I couldn’t be happier with my decision. The flow is a bit slower which has been great for my baby. He is very comfortable with this nipple and seems to use the same amount of effort suckling compared to nursing. To avoid any nipple confusion, the nipple features a wide base that mimics breastfeeding and that’s something I like about it because my newborn is comfortable with combined feeding and doesn’t have any preference yet. This has really made my life easier as a mom.”

Brianna preferred Dr. Browns

Brianna Leonhard is the founder of Third Row Adventures. She is a mom of a 4 year old, a 2 year old, and is pregnant with the third. She said:

“I tried 8-10 different bottles with my firstborn because he was so colicky. Philips Avent came highly recommended to us as a more natural option because the nipple had more of a breast-like shape (he could not nurse so I pumped some and supplemented it with formula).  However, it did not work well for him. Though it is more naturally shaped, it has less grip than other bottle nipples which made it harder for him to latch to. The base of the nipple is not very wide where it meets the plastic rim. He would gulp and grab at it like a fish which caused him to suck in excess air, making his present gas situation even worse. We eventually transitioned to Dr. Browns and saw a marked improvement in the severity of the gas after feedings and in colic.

Photo of Dr Brown baby bottles

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These were the ones we used and loved! They are shaped similarly to the Avent naturals but the nipple base is wider which gives baby more room to grip. They also have a built-in anti-colic feature!”

Katie loves it so much

Katie of KT Likes Coffee said:

“I am a mom that used Avent nipples with my child. She was actually breastfed, but eventually, I switched to exclusively pumping so she was fed breast milk in a bottle. 

I love Avent nipples, it was the only brand we could get my daughter to take a bottle with. They have a number of different flow options and the number 4 flow (for ages 6M+) worked great for us after I switched to exclusively pumping when she turned 5/6 months. I can’t recommend Avent enough!”

Rachel loves it

Rachel Taylor is a mom of 3, a Postpartum Nurse, postpartum doula, founder of Mama Did It, and a Spinning Babies® Certified Parent Instructor. She used Avent bottles and nipples with 3 of her babies. She said:

“Though we tried several varieties of bottles, we always went back to Avent. I liked that the bottles and nipples didn’t have several parts to put together and take apart. They are straightforward, easy to clean, and do the job. I also really liked that they offer different “flow” nipples. One of my babies would get mad if their milk didn’t come fast enough and another would choke if it came too fast. The different flow nipples allowed us to choose what was right for each baby.” 

When should I change my baby’s nipple size?

There are many signs to tell when a baby needs a change of nipple size. 

However, if you are strictly breastfeeding and want to move to bottle feeding, start with the newborn nipple size. This is because the newborn nipple size mimics the natural flow from the mother’s breast which your baby is used to. Trying any other size may be problematic for them as they would battle to take in more milk at once than before.

If you have been bottle feeding for a while, your baby needs a nipple change in the following situations:

  1. If your baby overspills during feeding

If your baby spills over milk when they didn’t do that before, or spills more milk from the sides of their mouth than before, it may be time to change the baby’s nipple again. 

Babies spill milk because they cannot keep up with the amount that is coming in no matter how much they try. Hence, milk leaking from the middle or sides of the lips is a sign that the flow rate is too fast. Use a slower nipple rate. 

Also, if a nipple’s flow rate is too fast, it can choke your baby and that’s harmful.

  1. If your baby frequently pulls away from the bottle and cries

If your baby frequently cries and pulls away from the bottle when feeding, it could be a sign that they are frustrated with the amount of milk they are getting from the bottle. This means that the bottle flow rate is too little to suit their needs. 

Another sign of an insufficient flow rate is if your child takes longer than 30 minutes to finish drinking a bottle. Resolve this by choosing a nipple with a faster flow rate.

However, every baby is different. 

Photo of a woman feeding her child

Tips from moms on when to change your baby’s nipples

Michelle says you can’t trust the age guidelines

Michelle McCarthy is the founder of FreshFlowersandSpilledMilk. She said:

As a mom of 2 young boys, I’ve experimented with many different feeding methods, bottles, and Avent nipple sizes. My first had acid reflux and my second had a milk protein allergy and a little trouble gaining weight (we had to fortify his milk). I would advise new moms to disregard some of the age guidelines and just use what seems to work best for their baby! When babies become uninterested, frustrated, or it is taking too long to finish a bottle, these are all good signs that you can go a size up. If they are choking, spitting up excessively, or finishing their bottle too quickly, these are all signs that you can go down a size. Every baby is different!

Rachel recounts her experience

Rachel Taylor is a mom of 3, a Postpartum Nurse, postpartum doula, founder of Mama Did It, and a Spinning Babies® Certified Parent Instructor. She said:

“Avent offers 5 different nipple sizes for babies. These sizes determine the flow of the milk: how slow or how quickly it comes out. Size 0 is the slowest flow and is recommended for newborns or new babies who are choking with feedings. Size 1 is also recommended for newborns. This size is more standard for a newborn, though some may need a size 0 to start. Size 2 is still considered a slow flow nipple, but is more appropriate after one month old as your baby is hitting growth spurts and wanting more milk at a faster speed. Size 3 is medium flow. And Size 4 is fast flow. Size 4 is usually used more as your baby can hold their own bottle and may be eating solid foods as well. 

As a mom, I chose a size 1 for my babies to start with. They were able to nurse and bottle feed well without choking on the milk flow, so this was the right size for them. At one month old, we increased to size 2 as they felt hungrier and were more eager to feed. We skipped size 3 and by 6 months old, they were at a size 4. Drinking bottles quickly and eating solid foods. 

You can tell it’s time to move to a faster flow nipple when the baby is collapsing the nipple when trying to feed.”


Can slow flow nipples cause gas?

A slow-flow nipple can allow more air to be trapped in your baby’s stomach because it does not have enough space for air release. However, Avent’s slow flow nipples have anti-colic valves that create a vacuum in the bottle to retain air. This reduces the amount of air that gets into your baby’s stomach.

How long should it take for a baby to finish a bottle?

It should take between 15 and 20 minutes for a baby to finish feeding from one bottle. However, it could be as short as 10 to 15 minutes if the flow is fast or up to 30 or 45 minutes if the flow is too slow.

Consider changing your baby’s nipple if you notice that it is taking more time for them to feed enough from a bottle.

What nipple can I use when I start mixing cereal into the bottle?

You will need a nipple with a fast flow to accommodate the thicker liquid. Avent provides this nipple size. But you can go for their variable nipple size which you can adjust to suit your baby.


You can tell if your baby has issues with their nipples by paying attention to their reaction when bottle feeding. The right nipple size will deliver the right amount of food to your baby and prevent crying and fussiness.

Avent provides great nipple sizes that suit your baby’s needs per time. 

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