How To Determine Flange Size For Breast Pump. finding the proper size for a breast flange is based on the diameter of the nipple, not the areola (the softer pigmented skin around the nipple). flange sizing guide instructions.
to determine your flange size you’ll need to measure your nipple. Use a ruler or measuring tape to find the diameter of your nipple (the horizontal width across it) in millimeters (1 cm. that’s fine, as most pump kits come with different flange sizes or you can order more.
Flange Size Chart
Flanges are not one size fits all, and having the right size flange will make a diffe. Most pumps come with 24mm size flanges to fit the 24mm size. It forms a vacuum seal around your areola, and then draws your nipple into its funnel to extract milk. if you measure up to 17mm, you’ll fit in a 21mm flange.
