breastpump flange size chart

Breastpump Flange Size Chart

Choosing correctly fitting breastpump flanges, also known as breastshields, is imperative when using a breastpump.  Breastpump flanges and breastshields fit directly over your nipple to form a seal around the areola and creates a vacuum, gently drawing your nipple into the tunnel for milk extraction.  When your breastpump flange fits correctly, you will not only enjoy a more comfortable pumping experience, but you will maximize the amount of milk extracted each time you pump. Let’s breakdown breastpump flanges with a breastpump flange size chart and explain the why and how behind this import piece of your breastpump kit.

Breastpump Flange Size Chart

Keep in mind that breastpump flange fit can change with birth, breastfeeding and using a breastpump.  What fits you well when you began breastfeeding or using a breastpump may need to change so it is important from time to time to recheck your breastpump flange fit.

Breastpump flange fit will fall into the following categories:

  • Good Fit: During pumping your nipple is able to move freely in the breastpump flange tunnel. You will have space around your nipple and not much of the areola is drawn into the tunnel with the nipple.

breastpump flange size chart

  • Too Small: During pumping some, or your entire nipple rubs against the sides of the breastpump flange tunnel.

breastpump flange size chart

  • Too Large: During pumping more of your areola is drawn into the breastpump flange with your nipple. You may experience your areola rubbing up against the side of the breastpump flange funnel.

breastpump flange size chart


When determining the right breastpump flange size, remember the word ‘COMFY’.  This term was specifically designed to help moms just like you remember five guidelines about breastpump flange sizing.

  • C – Centered nipple which moves freely.
    • Your nipple should move freely in the breastpump flange tunnel. You should not experience any rubbing; if you do, this indicates your breastpump flange is too small.
  • O – Only a little or no areola tissue is pulled into the tunnel.
    • If your nipple is able to move freely in the breastpump flange tunnel you will notice there will be a gentle pulling movement in the areola each time your breastpump cycles. If there is no movement in the areola, your breastpump flange is more than likely too small.  On the contrary, if there is a lot of movement or a large amount of your areola is pulled into the tunnel your breastshield is probably too big.
  • M – Motion of the breast is gentle and rhythmic with each cycle of the pump.
    • You should see gentle breast movement with each cycle of the pump just as you do with your nipple. Gentle breast movement indicates your breast is getting proper stimulation while pumping.
  • F – Feels comfortable pumping.
    • Using a breastpump should not be uncomfortable for you nor should it cause nipple pain or tenderness. If you experience pain or discomfort, more than likely you have an ill-fitting breastpump flange.
  • Y – Yields a well-drained breast.
    • Your breasts should feel soft after each use of your breastpump.

Incorrectly fitting breastpump flanges can affect how your breasts empty and yield problems with your milk supply.  If you use ill-fitting breastpump flanges for too long you could experience mastitis and even problems with low milk volume.  We hope this breastpump flange size chart has helped you determine if your breastpump flanges fit correctly.  If you have any questions regarding breastpumps or breastpump flanges give us a call at 844-867-9890.  As always, if you are interested in getting your free breastpump through insurance, we can help with that as well.  Simply fill out our Qualify Through Insurance form and you will be on your way to a new breastpump at no charge to you!  We look forward to helping you and your growing family.


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