
Why is there so much conflicting information when it comes to flange sizing?
➡️The traditional school of thought is to measure your nipples and add 3-4mm for your flange size. (Example, if you measure 15mm, select a 18-19mm flange)
➡️The newer school of thought that is being presented to lactation professionals through professional development right now is to size a momma much closer to her exact nipple size. (Example, if you measure 15mm, select a 15-16mm flange)
What do I believe?🤔 Personally and professionally, (After two exclusive pumping journeys and hundreds of flange sizing consultations) I lean toward the traditional school of thought, and I usually suggest a range of anywhere from 2-4mm larger than the nipple width. I would never suggest a 15mm flange for a 15mm nipple. Nipples expand during pumping, and I feel that there should be room for that expansion.🤗
That’s why I give mommas all the information and let them do a bit if experimentation to see what works for their unique body. ❤️ Want a little TMI? My nipples are 15mm and I comfortably use a 18mm Lacteck or 19mm hard plastic flange.
⚠️HOWEVER, flange sizing is SO MUCH MORE than “here, go measure yourself.” Mommas don’t usually know where/what to measure, and there are other factors that play into successful flange sizing than measurement alone. What are those factors?
⭐️FIT- Flange stays centered and does not gap or slide around
⭐️FEEL- Pumping is comfortable without pain to the nipple or areola
⭐️SPRAYS- Strong sprays of milk are a good sign it fits well (and good suction/settings on your pump).
⭐️EMPTYING FULLY- Meaning that milk is not left in areas of the breast/frequent clogs
⭐️EFFICIENCY- Sessions that take 15-30min max.
😵💫Confused? This is why a flange sizing appointment can be helpful! You don’t have to figure it all out on your own, momma! Get sized by a knowledgeable lactation professional.
Where do I measure?
For some mommas, it is unclear where the areola ends and the nipple begins. For many, the nipple has a different texture or skin tone shade than the areola. (The nipple may have a more textured/wrinkly appearance than the area around it) Gently pinch your nipple before measuring. Nipples cn get squashed inside bras and additional stimulation can help elongate/define the nipple.



How do I go about measuring my nipple?
Grab a ruler or tape measure with centimeters. Hold the centimeter side toward your body. It helps to get a second opinion, since you can only see it from one vantage point. From the picture on the far left, you can see that the nipple is about one line short of 1.5cm (this would be 14mm) See how it might be easier for someone else to look head-on, rather than you looking down from above? A caliper might work best, if you have one! (LINKED HERE)
If you are using a circle ruler (LINKED HERE), you want the circle that fits best without room to wiggle around (too large) and without catching onto your nipple skin as you put it on (too small). The circle ruler should encircle your nipple only and sit against your breast. (That’s how you know you are measuring the base of your nipple.)
A nipple of this size would most likely fit best in anywhere from a 15-18 flange size, depending on comfort and efficient and full milk removal.
Not to sound like a broken record, but this is another reason it helps to get professionally sized. It can be difficult to do on your own!



How do I measure a flat nipple?

“Rolling out the nipple” can help a flat nipple evert/become erect for measurement. Check out this video for an example of rolling out the nipple: VIDEO HERE (Starts at :34 timestamp) Video from IABLE: Institute for the Advancement of Breastfeeding and Lactation Education
Beginning to pump before measuring, or using a nipple everter like THIS one, can help make an inverted or flat nipple more evert and easy to measure.
Okay, but can we see a flange sizing video, please?
You got it, dude.
When do I measure myself?
I suggest waiting until AFTER birth to measure. Also, it’s a good idea to measure before pumping, not after. Nipples expand (or “puff up” during pumping and you may not get an accurate size after pumping.)

How do I select a type of flange when there are so many options out there?
Pumping is all about experimentation, momma! But where to begin? Let me introduce you to some of my favorite options:
- Hard plastic flanges:
Many companies carry a limited range of sizes. Check AMAZON for a greaster variety of compatible flange sizes - Lacteck silicone baby-motion flanges:
Pump Momma Pump’s absolute favorite! Made of soft, flexible silicone, these can provide additional comfort and are a great option if hard plastic flanges don’t feel that comfortab;e, even when using your correct flange size. Save on lacteck by using code PUMPMOMMAPUMP10 and learn more over at lacteck.com - PumpinPal flanges:
These are angled, gradually tapered flanges which come in a variety pack so you can try out different sizes to see which works best. I usually suggest these for women struggling with elastic nipple tissue (more about this below) To save on PumpinPal flanges, use code PUMPMOMMA5 and click HERE to learn more! - BeauGen Flange Cushions:
Soft and sticky, these cushions can be added to your hard plastic flanges to provide a secure grip and soft feel. They are my go-to suggestion for mommas struggling with elastic nipples or leaking when using a wearable pump. Here’s your LINK for these cushions! (Note that they fit into flanges size 21-27 and reduce the flange size by about 2mm.)


What about Elastic Nipples?
How do you know if you have Elastic Nipples? 🤷♀️
(and what does that even mean???)
Our skin is elastic (I mean, just think about how much our skin stretches in pregnancy, doesn’t it!) and all nipples swell during pumping. However, some mommas have more elastic tissue in their nipples that can be problematic when pumping.

Elastic nipple tissue has greater “stretchiness”/elasticity than other nipples. They can swell widthwise to fill any size flange tunnel and/or stretch down the flange tunnel and even hit the end of the flange tunnel. How do you know whether you have elastic nipples? Notice how the nipple in “Too big” image below doesn’t stretch, it sits atop a “nipple mountain” of too much areola being pulled into the tunnel. That nipple is not elastic. The nipple in “too small” is also not elastic, it’s being squeezed into a flange tunnel that is too small.
So what do you do if you have elastic nipple tissue? You cann’t turn elastic nipples INelastic (like you can’t make that go away) so you just have to work with it. You get sized professionally for the correct size flange, and you find the size and style flange that is both the most comfortable and fully empties the breast most efficiently. This can mean selecting a flange cushion, a silicone flange, an angled flange, and/or adding or eliminating lubrication while pumping. Confused? That’s why it’s best to work with a lactation professional 1:1 to figure this out!

Additional Tips
Flange sizing can REALLY improve your breast pumping journey. A well-fitting flange can increase comfort, help you empty quicker, and ensure that you’re fully emptying each time you pump. However, there are other factors that can also help. Adding a lubricant like a food-grade coconut oil to your areola/nipple before pumping can greatly reduce friction and increase comfort (especially if you are sizing down in flange size from what you were using before.) Making sure you change your valves regularly (every month for exclusive pumpers and every three months for occasional pumpers) will ensure that your suctions stays strong. Keeping your flange centered on your nipple will help you fully empty without keeping milk in part of the breast due to uneven suction on your milk ducts.

