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Finding the Right Flange: Eliminate discomfort, increase supply, and (finally) pump in peace.

Follow these tips for finding the right flange for your needs. Learn to find the size and type you need to eliminate discomfort and help your supply flourish.

When I first started pumping, I couldn’t tell you what a flange was if my life depended on it. I was just an overtired mom trying to feed a baby who wouldn’t nurse, and the diagram in the instruction booklet said to put the suction-cup looking thingy on my breasts.

Turns out that “suction cup thingy” was the flange. And it would be way more important to my pumping journey than I realized.

What I know now, after feeding three babies and helping thousands of moms on their pumping journey, is a flange can make or break your milk supply.

If you don’t have the right flange, you could be missing out on making the most milk available to you. Instead of a peaceful and productive pumping session, you could be suffering simply because you don’t have the right flange.

But not on my watch. By the time we’re through here, you’ll be able to identify a flange out of a line-up of pump parts, plus find the size and type you need to eliminate discomfort and help your supply flourish.

Ooh, I’m pumped just thinking about it.

Finding the Right Flange

What is a flange?

While I’m still partial to my original definition of “suction cup thingy,” this is the part of the blog where I share my knowledge as a certified lactation counselor. So here’s a more professional definition:

Flanges are the plastic, funnel shaped pieces that come with your pump, and are designed to fit over your nipple. 

Finding the Right Flange

When you turn on your pump, your flange creates a seal against your skin and uses suction to stimulate your nipple so it will release milk.

Flanges are typically made of hard plastic, and come in one piece or two pieces.

Finding the Right Flange
types of Flange


Why does flange size matter?

Think of your flange like a pair of shoes. If you’re going to wear them everywhere, you want them to fit. You don’t want to be sliding in and out of a pair that’s oversized, and you definitely don’t want the pain and blisters from a pair that’s too tight. Either way, it’s hard to get where you want to go when your shoes don’t fit.

It’s the same for your flange.

When your flange is too big, you’ll spend all your time repositioning your breast, and won’t be able to make the most of your 20-25 minute pumping sesh. 

When your flange is too small, the discomfort makes it hard to pump long enough to stimulate a let-down and capture your milk.

So even though your pump most likely came with a standard 24mm flange, there’s a good chance it isn’t the right size for you. And if you’re wearing the wrong size flange, you’re either going to be incredibly uncomfortable, incredibly frustrated—or both.

And you for sure won’t be getting the amount of milk you want out of the pumping process.

If you want to empty your breasts efficiently and effectively, without pain and discomfort, every single time you pump, you need a flange that fits.

How do I find the right flange for me?

First, measure your nipples

Finding the perfect flange starts with measuring your nipples. This measurement is simply a reference point so you can start to narrow down your search for the right-sized flange. It’s like the shoe analogy we talked about earlier. The first step in finding the right pair of shoes is to have the employee measure you. We’re going to do the same for your flange.

You can follow the steps below or watch this video to measure and size your nipple.

  1. Start by printing this free flange ruler and cutting it out. You’ll use this to measure each of your nipples, as it isn’t unusual to have two different sizes.
how to measure nipples

Before you measure your nipples, pump or nurse for about 10 minutes. We want to get the most accurate measurement possible, and since nipples swell during pumping and nursing, we want to capture them at their expanded size.

  1. Using the ruler section of your flange ruler, measure the width of each nipple.  You’ll need to remember roughly how many millimeters each one is, so write that number down if needed.
measure nipples
  1. Now find the row of circles on the flange ruler that includes your nipple measurement and cut through the dotted line. 
cut along the dotted line
  1. Then cut out all the semi-circles along that line.
cut out all the semi circles
  1. Finally, place your nipple into each semi-circle to find the one that fits best. You want your nipple to slot right into the semi-circle seamlessly, without stuffing it in or having a bunch of extra space on the sides. 
place nipple into each semi-circle

The number next to the semi-circle your nipple fits in is your flange size.

Then, explore flange sizes and types

Let’s go back to the shoe store comparison again, shall we? Once the salesperson measures your foot, they bring out a bunch of shoes for you to try. But even though the ruler said you’re a size 8 shoe, the salesperson might bring out anything ranging from a 7.5 to a 9. Why? Because every foot is a little different, and every shoe brand is too! There’s a reason they have to try on a range and walk around for a bit to see what feels best.

But how do you do that with flanges?

By watching videos of nipples similar to yours and how they fit in specific flanges.

Okay, I may have just lost some of you because you just got really weirded out. But trust me—I’ve helped over 3,000 moms size their flanges and they tell me time and time again how helpful it is to see what their nipple is supposed to look like in their flange.

flange videos review

That’s why my Ultimate Pumping Course features videos of nipples (both regular and elastic) from size 13-36, in both plastic and silicone flanges.

Because while most moms can eliminate discomfort and pump efficiently with a plastic flange in the right size, some moms discover they have elastic nipples and need a silicone flange instead.

While all nipples have some stretch to them, elastic nipples are extra stretchy and get pulled too far into the flange tunnel during a pumping session. When this happens, your milk ducts are compressed, milk flow is cut off, and the pain is off the charts. A silicone flange gives an elastic nipple more room to expand width-wise so it doesn’t get pulled so far into the flange tunnel.

If you’ve sized your nipple correctly, compared your nipple to those like yours, tried both a plastic and silicone flange, and are still having pain and discomfort, it’s time to assess your pump settings, and double check your flange one more time. The Ultimate Pumping Course can help you troubleshoot the other factors that could be contributing to your struggles.

Finally, buy and try your new flange

Here at One With the Pump, I’m all about making your life easier. 

One of the ways I do that is by trying all sorts of products so you can skip directly past what doesn’t work and go straight to what does. The Flange section of my Amazon shop will take you directly to the best plastic and silicone flanges. 

If you can’t find a compatible flange in your size, you can buy a flange insert in the size you need. Flange inserts go inside any flange making it the right size for you. Flange inserts are also needed if you use a wearable pump of any kind. 

Trade confusion for confidence.

Having the right flange is just one piece of the pumping puzzle. So what if you could take the guesswork out of your entire pumping journey?

With the Ultimate Pumping Course, you can.

Through bite-sized videos, I’ll teach you how to:

  • Confidently pump and nurse from day one
  • Choose the right pump and make the most of your pumping sessions
  • Create a pumping schedule that supports your short and long term needs
  • Eliminate pain while pumping
  • Size your own flange
  • Establish, maintain, and manage your milk supply
  • Prevent common pumping problems
  • Utilize pumping full-time or alongside nursing as part of your overall feeding plan

You can pump efficiently, effectively, and confidently—from your first feed to the last. The Ultimate Pumping Course will show you how. Get instant access and be one with your pump, starting today.