Finding Your Perfect Flange Fit –A First-Time Mom’s Guide
Breastfeeding and pumping can feel like a whole new world, but finding the right fit for your breast pump doesn’t have to be complicated.
Getting to Know Your Body – The Basics of Breast Anatomy
Before diving into measuring, it’s helpful to know a little about your breasts and how they play a role in pumping success.
The Nipple: This is the center of attention for pumping – it needs to fit comfortably into the breast pump flange.
Areola: The darker area around your nipple. While it might slightly enter the flange, the goal is to ensure most of the suction focuses on your nipple.
Milk Ducts: These lie beneath the surface of the nipple and areola, delivering milk during pumping or breastfeeding. Proper flange sizing helps milk flow efficiently from the ducts.
When is the Best Time to Measure your Nipples?
Your nipples can change in size during a pumping session, often swelling and becoming larger as you pump. This swelling can affect the fit of your flange, so it’s important to measure your nipple accurately to ensure comfort and effective pumping. The best time to measure is right after breastfeeding or pumping when your nipple is at its largest. If that isn’t possible—whether your baby isn’t available or you’re preparing before your baby is born—you can measure your nipple at rest and add approximately 2mm to account for the swelling that typically happens during feeding or pumping.
Having a few flange sizes or inserts on hand—one that matches your measurement and others slightly smaller and larger—can help you find the best fit. The flange is the part of the pump that directly fits over your breast, while inserts are used to adjust the flange size for a more precise fit.
If the flange feels too large, using an insert can help reduce the size without needing to purchase multiple flanges. Keep in mind that using the wrong size, whether it's the flange or insert, can cause nipple swelling.
Flange Fit During Pumping
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| TOO SMALL |
A flange that is too small can cause friction as the nipple moves through the tunnel and may result in pain and damage. |
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| GOOD FIT |
Your nipple should be able to move gently in the flange tunnel without pain. |
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| TOO LARGE |
A flange that is too large can allow too much of your areola to enter the flange tunnel and can result in painful swelling and rubbing. |
Two Ways to Measure: Using a Nipple Ruler or a Standard Ruler
Measuring with a Nipple Ruler:
Step 1: Measure your nipple right after pumping or breastfeeding for the most accurate size (DONT SKIP)
However, if you need to determine your flange size before your baby arrives or before you begin pumping, you can still measure your nipple at rest. In this case, add approximately 2mm to the measurement to account for swelling that typically occurs during pumping or feeding
Nipples are not always the same size. Measure each nipple individually since you may not get the same measurement for the left and right.
Step 2:Place each nipple into the circular guides on the measuring tool below to find your best fit. Measure each side separately as they measure differ.
Step 3:Slide the hole over each nipple. Select a hole with a nipple diameter that fits snugly around the base.
Refer to the Nipple Size Chart to determine the flange or insert size that fits you best.
Measuring with a Regular Ruler or Tape Measure:
Step 1: Measure your nipple right after pumping or breastfeeding for the most accurate size (DONT SKIP). Sit in good lighting. Make sure your nipple is slightly erect for the most accurate measurement.
ONLY measure the diameter of your nipple excluding the areola in millimeters, from top to base.
Nipples are not always the same size. Measure each nipple individually since you may not get the same measurement for the left and right.
Step 2:Align the edge of the ruler with your nipple’s base and measure across the diameter.
Step 3: Mark the Size: Write down the millimeter measurement and add 1-2mm for comfort
Refer to the Nipple Size Chart to determine the flange or insert size that fits you best.
Nipple Size Chart
