Written by the team at The Baby Element Clinic, Wilmslow. Last updated: 8 May 2026.
For mums who are expressing, your breast pump is a wonderful tool for sharing your amazing milk with your baby. But here is a little secret: a simple piece of plastic—the flange—can be the difference between a relaxing, productive session and one that feels like a total chore.
At The Baby Element Clinic in Wilmslow, we’re all about making your feeding journey smoother. We use the FLANGE FITS™ method (Feel, Intensity, Tempo, and Supply) to help you find that “just right” fit, so you can stop “tolerating” pumping and start feeling supported.
Think of the flange as the funnel that creates a gentle seal to draw your nipple in. Because every body is beautifully unique, “standard” sizes rarely fit everyone.
When your flange fits perfectly:
You’ll see more milk: A good fit helps the pump empty your breast effectively, which tells your body to keep that supply coming.
You’ll stay comfortable: Pumping should feel like a gentle tug, not a pinch.
You’ll protect your skin: You’ll avoid the friction, redness, bruising and blisters that come with a poor fit.
You’ll stay healthy: Better milk flow means a lower risk of painful blocked ducts or mastitis.
It’s hard to know what’s “normal” if you’ve never done this before. While many pumps come standard with 24mm to 30mm flanges, newer clinical evidence suggests these are often too large, as the majority of people actually need a size under 20mm.
| If it’s TOO SMALL | If it’s TOO LARGE |
| Your nipple rubs against the sides of the tunnel, which can really sting. | A lot of your areola (the dark circle) gets sucked into the tunnel and can swell. |
| Milk flow feels restricted because your nipple can’t move freely. | You might notice more “drips” than “sprays” of milk. |
| Your nipple might look white, red, or even misshapen after you finish. | You might feel like you aren’t “empty” after pumping. |
We recommend checking your fit every so often, as your body can change throughout your journey. And remember; your bra size, areola size or breast size has nothing to do with your flange size!
Measure the width of the nipple tip (not the base) in millimetres. Check both sides, as they are often different!
Try a few different hard plastic sizes. In an ideal fit, only your nipple is pulled into the tunnel, and it should glide back and forth while touching the walls. This usually results in those satisfying sprays of milk. You can trial the silicone inserts to find the closest size first before investing in the harder plastic ones.
Intensity: Start low and only turn it up if it feels good and helps the milk flow.
Tempo: Start fast to get things moving, then switch to a slower rhythm once you see sprays. If the milk slows down, go back to fast or “letdown” mode for a minute or 2 to “reset”.
Ideally, you should see or hear sprays for most of your session. If you only see drips and dribbles, it might be time to reassess your fit or pump settings.
If you’re feeling overwhelmed by parts, sizes, and settings, you don’t have to figure it out alone.
At our clinic in Wilmslow, we provide expert, hands-on support to take the guesswork out of feeding.
Our International Board Certified Lactation Consultant (IBCLC), Nikki Mather, can help you with:
Professional Flange Sizing: We’ll measure and test together using the latest clinical guidance to find your perfect match.
Pumping Troubleshooting: From pain to low supply, we’ll get to the bottom of it.
Optimising Your Routine: We’ll show you “hands-on” techniques to get more milk in less time.
Total Feeding Support: Whether it’s latching, supply, or just a bit of reassurance, Nikki can support you from a holistic view.
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