Determining Which Flange Size is Right For You

Breast pumps have become indispensable tools for many mothers. They provide flexibility, convenience, and the ability to balance breastfeeding and daily routines. A crucial aspect of using a breast pump is ensuring the flange is the right size for your body. Without the right flange size, breast pumping moms may experience discomfort and spillage, obstacles that may hinder a mom’s breast pumping journey. Luckily, they can be easily avoided by knowing your flange size. 

At Pumps for Mom, we want to ensure moms have all the maternity accessories they need for pumping success. Part of knowing what maternity accessories are best is also knowing the right fit. In this guide, we’ll delve into the following:

  • Defining what a breast pump flange is.
  • Exploring the importance of a correctly fitting flange.
  • Learning how to determine the right flange size for you.

What is a Breast Pump Flange? 

The flange is the funnel-shaped piece of a breast pump that fits over your breast. Once the breast pump is turned on, the flange helps create a seal to express milk efficiently.

Pumping should not be a painful experience. An appropriate flange size ensures successful milk expulsion, comfort, and discomfort prevention. Poorly fitting flanges can cause friction and suction issues that, over time, may cause inadequate milk removal. The continuous use of a poorly fitting flange may also result in nipple trauma. As a vital maternity item, it’s crucial to ensure your flange fits properly.

Determining the Correct Flange Size

Every mom’s body is unique, and the right flange size for you might differ from someone else’s. Investing time in finding the ideal fit will contribute to your overall breastfeeding success and well-being. Here are some steps to take to determine your ideal flange size: 


Nipples come in all shapes and sizes and vary widely among people. Knowing the shape and size of your nipples can help you become familiar, at least visually, with your ideal flange. Observation is a good first step for moms wanting to get a vague idea of their needs. They should always follow up a visual examination by properly measuring the area. To help you properly size your flange, use this easy sizing chart from Willow


Getting to specific numbers and figures will help you make the best decision. Using a ruler, measure the diameter of your nipple at its base. Write down the numbers and keep them handy when ordering your breast pump through insurance. If you are able, bring any questions you may have to your lactation consultant. 

Fit Test

Time to put all the collected information to the test! During your pumping session, your nipple should be able to move freely within the flange tunnel without rubbing against the sides. There should be enough space for expansion without excessive areas of the areola being pulled in. If pumping becomes painful or the output of milk remains low, you should consider a different flange size. 

Selecting the correct flange size for your breast pump is a pivotal step in ensuring a successful breastfeeding and pumping journey. At Pumps for Mom, we want moms to know all they need for a smoother breast pumping experience. That’s why we offer a range of incredible breast pumps through insurance and maternity accessories to set you on the right track. Head to our easy-to-fill form to get your perfect breast pump, or contact our team today!