Finding the Right Breast Pump Flange Size

Did you know the standard breast pump flange size is based off of dairy cows? Have you ever seen an udder? 😳 Oftentimes, the flanges that come with a pump are too large, leading to inefficient pumping.

A pump flange is the part of a breast pump that fits over your nipple to help express milk. Choosing the right size is essential for comfort, milk flow, and overall effectiveness. Too small, and it can pinch or restrict milk flow. Too large, and it can pull in too much of the areola, leading to discomfort and less efficient pumping.

How to Properly Size Yourself for a Pump Flange

Thankfully, sizing for a pump flange is much simpler than you might think! Here’s how:

1. Measure the Base of Your Nipple
   Use a ruler or measuring tool to measure the base of your nipple (not the areola) in millimeters.

2. Add 1–2 Millimeters
   Once you’ve measured, add 1–2 millimeters to determine your ideal flange size. For example, if your nipple measures 18 mm, your flange size would likely be 19–20 mm.

That’s it! A properly sized flange should feel comfortable and allow for effective milk expression without pain or irritation.

What Does a Good Flange Fit Look and Feel Like?

Not sure if you’ve found the right size? Here are some signs that your flange is fitting properly:

1. Your Nipple Moves Freely in the Tunnel
   During pumping, your nipple should move smoothly in and out of the flange tunnel without rubbing against the sides. If it’s rubbing, your flange might be too small.

2. Minimal Areola is Pulled In
   Only your nipple (or just a tiny bit of the areola) should be pulled into the tunnel. If too much of your areola is being drawn in, your flange could be too large.

3. Comfortable Suction
   Pumping should feel like gentle suction—not painful pulling, pinching, or tugging. Pain is often a sign that your flange size or positioning needs to be adjusted.

4. No Redness, Blisters, or Irritation
   After pumping, your nipples should look and feel normal. Redness, swelling, blisters, or irritation are signs that something isn’t quite right.

5. Effective Milk Expression
   With the correct size, you should notice good milk flow during pumping. If you’re not seeing much milk or feel like your breasts aren’t being emptied, you might need a different flange size.

Extra Tips for a Better Pumping Experience

• Experiment with Different Sizes: Everyone’s anatomy is different, and your nipple size can even change throughout your breastfeeding journey. Don’t be afraid to try different flange sizes to find what works best for you.

• Check Your Pump Settings: If the suction level feels too strong or weak, adjust your pump settings. Proper suction, paired with the right flange size, can make a world of difference.

• Lubrication Helps: Applying a tiny bit of nipple cream or coconut oil to the inside of the flange can reduce friction and improve comfort.

• Reassess Over Time: Your flange size might change due to engorgement, swelling, or as your breastfeeding journey progresses. If pumping starts to feel uncomfortable again, it might be time to reassess.

Still Struggling?

If pumping still feels uncomfortable, or if your milk output isn’t where it should be despite using the "right" size, don’t hesitate to reach out to a lactation consultant.