Mother’s Hug Breast Pump Flange Size Guide

What is a Breast Pump Flange?

The breast pump flange is the part that rests against your breast during pumping. Shaped like a funnel, it creates a vacuum seal around the areola, drawing the nipple into the tunnel where the milk is extracted. Flanges are typically made of plastic or silicone and are available in different sizes to suit various nipple shapes and sizes.

Some pumps include multiple flange sizes or silicone inserts that reduce the tunnel opening for a more tailored and comfortable fit, improving both milk flow and overall comfort during pumping.

Why Flange Size is Important

Choosing the right flange size plays a crucial role in your comfort and pumping effectiveness. A properly fitted flange can help increase milk output, avoid nipple pain or damage, and make the pumping experience more efficient and pleasant.

Flanges usually range in size from 13mm to 36mm, depending on the brand. The size refers to the inner diameter of the flange tunnel—not the outer edge. Mother’s Hug pumps typically come with a 24mm flange and offer optional 27m

m sizes, along with insert sizes from 15mm to 21mm to cover a wide range of nipple sizes.

What Should Your Nipple Look Like in the Flange?

Your nipple should sit comfortably inside the tunnel without touching or rubbing the sides. The areola should stay outside the tunnel and not get pulled in. If the flange is too small, it may cause painful friction. If it’s too large, too much of the areola might be pulled in, leading to discomfort and reduced milk flow.

Too Small

Nipple rubbing against the flange

Correct Fit

Nipple snug nicely inside the tunnel of flange

Too Large

Nipple along with areola is being sucked into the flange

How to Measure Your Nipple for Flange Sizing

There are two easy ways to determine your flange size:

Method 1: Using a Regular Ruler

1. Stimulate your nipple to make it firm.
2. Place a ruler at a right angle to your body with the 0 mark aligned with the base of the nipple.
3. Measure the width of the nipple (not including the areola) in millimeters.

Method 2: Using a Nipple Ruler with Holes

1. Stimulate the nipple to make it stand out.
2. Gently insert the nipple into the circular holes one by one until you find a snug fit. The correct hole size is the one your nipple fits through completely, while the edge of the ruler touches the areola.

Choosing the Right Flange Size

Mother’s Hug includes a nipple ruler in every set to make sizing simple. Be sure to measure both breasts, as they can differ. We suggest adding 1–3mm to your measurement to accommodate swelling during pumping.

How Do You Know If the Flange Fits?

• Nipple movement: It should move freely in and out of the tunnel.
• Areola visibility: Only a small part of the areola should be drawn in.
• Comfort: There should be no pain or pinching.
• Post-pumping check: Nipples should look healthy, without redness or injury.

Can Flange Size Change Over Time?

Yes, breast and nipple size can change due to pregnancy, postpartum changes, or ongoing pumping. That’s why it’s a good idea to check your fit regularly and re-measure if needed. Adding 1–3mm to your nipple size when measuring before birth helps allow for swelling during pumping.

Still Unsure?

Reach out to our support team for help with sizing, fit, or insert selection.

FAQs

• What is the most common flange size? 24mm is the standard size for most moms, and it’s the default in most Mother’s Hug pumps.
• Does using the correct flange size improve milk output? Yes! A proper fit helps express more milk and avoids unnecessary discomfort.
• What happens if too much areola enters the flange? It usually means the flange is too large, which can reduce suction and cause soreness.
• What if I’m between sizes? Try an insert first. If you’re still in between, opt for the larger size for a more comfortable fit.