How to Test the Flow of Bottle Nipples

By Sara Ipatenco
The flow refers to how fast the liquid comes out of the nipple opening.
The flow refers to how fast the liquid comes out of the nipple opening.

All bottle nipples might look the same, but they really aren't identical. Nipples are made with an opening at the top, which allows your baby to suck the breast milk or formula out of the bottle, but the size of these openings vary from nipple to nipple. Determining the appropriate nipple size for your baby is essential because if the food comes out too slow, your little one could get frustrated and not get enough to eat. If it comes out too fast, your baby could gag, as well as eat more than she needs for proper growth. Fortunately, testing the flow of your baby's bottle is easy.

Place 2 or 3 ounces of breast milk or formula into your baby's bottle. It's essential to use the same liquid you'll be feeding your baby to determine the flow rate of the nipples. Different liquids will flow out at different rates and using the same food will allow you to most accurately gauge how fast it comes out of the nipple.

Attach the lid and nipple and screw it on tightly.

Turn the bottle upside down and watch to see how quickly the food drips out of the nipple opening. Do this with each brand of nipple that you plan on using. The flow rate can vary from nipple to nipple and testing each of the brands you use will help you determine an accurate flow rate for each one, according to pediatrician Dr. Natasha Burgert, writing for the KC Kids Doc website. If your baby is under the age of 6 months, look for a flow rate that is consistent and that comes out in drops. Older babies, usually those who are 6 months of age or older, might feed more efficiently with a nipple that emits a steady stream of food rather than consistent drops, the BabyCenter website notes.

Experiment with different brands and different flow rates if your baby doesn't feed well or if she shows frustration as she's drinking a bottle. Take note of the brand and "level" of the nipple your baby responds to best so you can continue using it in the future.


Most nipples are labeled with information about their flow rate. Most newborns and tiny babies should use nipples with the smallest opening, often labeled "stage 1," according to the BabyCenter website. Older babies might eat better with nipples that are labeled as "stage 2." If your baby has reflux, a slower flow nipple might make eating easier and more comfortable. If your baby is gagging, choking or if a lot of the food is dribbling down her chin, try a slower flow nipple, recommends Dr. Burgert. If your baby appears to be struggling to get the food out of the bottle or if she loses interest before the bottle is empty, try a faster flow nipple.

About the Author

Sara Ipatenco has taught writing, health and nutrition. She started writing in 2007 and has been published in Teaching Tolerance magazine. Ipatenco holds a bachelor's degree and a master's degree in education, both from the University of Denver.