What is my WHAT size? A simple guide on how to measure nipples to get a proper flange size.

So often in our line of work, we see new parents-to-be who feel pretty clueless about pumping and nursing having to rely on help once they get to the hospital with feeding their babies with their bodies. Many pregnant people don’t even realize that there’s more to take into account with pumping milk than which pump to buy or that they should know how to measure nipples. When people do get their pumps, the flanges inside are often much bigger than what one’s nipple size is. Some pump brands will send a nipple measurer, but that’s few and far between. Further, some people require a bit of help from a nipple shield in the beginning of their nursing journey, and proper size is important for that, as well (hint, the flange and shield are usually the same size). Your nipple size can also vary from one nipple to the other! 

What ends up happening is the pumping person simply washes/sterilizes their flanges and shields and off they go with nursing and pumping, not ever having been measured or taught how to use a flange or shield or having taken a breastfeeding class. Many people assume (myself included, back in the day) that the lactation consultants in-hospital, that come and visit us in our postpartum while we’re there, will set us up for success on our nursing and pumping journeys. While many are so, so helpful and want nothing more than everyone to successfully feed their babies with their bodies, unfortunately, they don’t have access to proper tools that will fit EVERYONE, nor do they have the time to really spend with people during those visits to measure and educate as needed. 

So, it’s up to us to know what size our nipples are so that we can bring with us to the hospital and have at home the proper tools that will help us better succeed on the body-feeding journey.

If you’re going back to work after having your baby, you will likely be pumping milk while away from the baby. If we’re not nursing to remove milk, we have to pump to remove milk or our supply can be affected. Most health insurance companies will cover the cost of one breast pump per pregnancy, sending you off to a website full of choices on pumps. (I’ll be doing a whole other blog on the different types of breast pumps soon) so let's just chat about common questions we get as Feeding and Lactation Specialists on nipples and flange size.

What is a flange and why do I need to know how to measure nipples? A flange is a plastic part of a pump that fits over the nipple to create a seal and vacuum (mimicking the suction a baby provides to the body). Making sure one has the right size flange is important not only for comfort reasons, but also because the wrong size flange (too large or too small) can impact milk output as well as the quality of milk that you’ll produce. You should know how to measure your nipples so that you can help set yourself up for breastpumping success.

How do I measure my nipples? Are there tools that I’ll have to buy? Most everyone at home has some sort of ruler or measuring device that has millimeters, and that’s all you need to be able to accurately measure yourself. But if you don’t have a ruler handy, you can download a ruler to your phone and measure it like that, or you can head to one of many sites listed below and print one of their measuring pages out to use for free. 

Nipples tend to swell or expand during a pump, so sizing yourself after a few minutes of pumping can give you a much more accurate size. If printing out a guide, you can use the circular nipple holes or the linear measuring tool, like a ruler. If using the circular cutouts, you want to make sure that the tool/paper itself is not tight on your nipple but does not have much space that it draws in your areola. 

The 20mm hole is nice and snug around the nipple without being too tight.

The 22mm hole is too big and leaves too much space around the nipple.

When using a ruler or linear measurer, you’ll want to make sure you’re ONLY measuring the nipple, from the diameter of the base of your nipple, from one side across to the other. 

Any standard ruler with MM can be used to measure the nipple, from one side across to the other.

How do I know which size to use after I measure? While the measurement is a great tool, it’s only a start. You want to look at what the manufacturer of the pump recommends for their flange sizes to get the closest size to your nipple. If that size isn’t comfortable because it’s too tight, size up. 

Because nipples vary from side to side and person to person, a good rule of thumb is to get your nipple size, and then try a flange between that size up to one that’s 4mm larger than the size you measured at. For example, if you measure at 15mm, you can go up to a 19mm (realistically) in flange size. You may have to play around with a few different sizes until you find a fit that feels right for you. As previously stated, your nipples may vary in size from one to the other, too. 

Some people prefer to buy a silicon insert that they can pop into whatever larger sized flange that comes with the pump, rather than change the flange completely. It offers a bit more cushion to the nipple and many prefer the soft inserts over the harder-plastic flange. 

What is a nipple shield and why would I need one? A nipple shield is a thin, flexible piece of silicone that fits over a nipple and designed to help babies who are having difficulties latching on to feed. They provide a slightly firmer, longer nipple for them to grasp onto. 

How do I apply the shield? The nipple shield is applied by turning the shield inside out, placing it over the tip of the nipple, smoothing it back out over the breast, making sure the nipple extends into the shield while a good seal is being maintained. Here’s a great video showing how it’s done: https://youtu.be/p2dK9tAaHY0?si=snMIrj8E2A4akEml

Why did the hospital give me a size 24mm breast shield if my nipple size is so obviously smaller than the shield? If you measure one size for a flange, you should use that same size for a nipple shield. If you have a smaller nipple than a size 24mm or 27mm, I would advise you to take your shield size with you to the hospital, as many hospitals only have those two sizes to offer people, and your baby will struggle to latch onto a nipple with a loose shield. They can also cause a lot of nipple damage by improperly sucking on the shield. 

Most people who use nipple shields, use them temporarily, for a number of weeks or months, while they’re learning how to feed, baby is learning how to feed, and/or grow (some premature babies struggle with the suck, swallow, and breathe pattern and have to grow and learn it). You want to make sure the shield is thoroughly sterilized before initial use, cleaned with warm soap and water after each use, and stored away properly to keep away any germs. 

Some babies do get used to the shield and have to be weaned off. The shield can also affect supply and transfer. But some of the benefits are that they allow your nipples to heal after trauma (maybe baby has an oral restriction and caused a wound), they give baby extra time to learn how to suck and feed, and they also allow you to continue breastfeeding and avoid formula. 

Many lactation peeps, Kelly and I included, offer our lactation services virtually and in-person and are more than happy to come to the hospital to help you in your postpartum right away! If you feel the in-hospital lactation consultant left you with more questions than answers, reach out for a second opinion. The more lactation help one can get, the better. Living in the days of social media also allows us easy access to online videos and blogs about breastfeeding and pumping; take advantage of them!

Whatever the reason for using a shield or a pump, know that you are doing your very best and just because you may need help with a shield for a while or have to pump to go back to work, that you’re doing an amazing job providing such a gift for your baby. Nursing and pumping are HARD work; the equivalent of a part-time job, according to some studies. Give yourself credit and try not to feel bad when you need to use the tools available to you during your journey. That’s what they’re there for and it doesn’t reflect AT ALL on your abilities. It’s a learning process, breastfeeding/nursing/pumping and it takes weeks for people to feel comfortable in that process. 

***Most pump brands will have an online page you can venture over to and download their nipple measuring tool to measure your own nipple!***