Choosing the Right Flange Size

January 14, 2022

What is a flange?

A flange, also known as a breast shield, is the part of the breast pump that rests on your breast during pumping. The cone-shaped funnel sits over your nipple, creating a vacuum-like seal around your areola to gently extract milk.

Why does size matter?

Choosing the correct size flange can make all the difference when it comes to pumping. If your flange is too small, it can cause unnecessary rubbing, resulting in nipple discomfort. If your flange is too large, it won’t extract all of your milk, resulting in lower milk supply.

We know this is a lot to take in. That’s why we’re here to help! Let’s measure together, Mama.

How do I measure?

To start, let’s measure the diameter of your nipple. Flange sizes are in millimeters so we want to use the same metric system. You can use a tape measure or ruler to measure across. Be sure to not include your areola, as the breast shield size is only pertaining to your nipple.

The standard size (included with most pump packages) is 24mm. However, this doesn’t mean it’s a one-size fits all. Not only can your size be unique, each breast can differ from one another. Please make sure to measure both nipples during this process.

Image from Medela

If the following is true, you are using the correct size flange:

Your nipple is centered and moves freely (but not too much).
After your pumping session, your breasts feel emptied and soft.
There is no pain or tenderness during pumping sessions.

An important thing to keep in mind throughout your pumping journey is that your nipple size can change. If you notice that you start to feel pain during pumping sessions or your milk supply is decreasing rapidly, we recommend remeasuring. Another great resource is scheduling an appointment with a Certified Lactation Consultant or reaching out to your pump's manufacturer to discuss possible causes.

For a limited time, we have partnered with Metropolitan Breastfeeding to offer you a FREE flange fitting consultation! Click here to schedule yours with Dr. McCue.