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Momcozy Breast Pump Flange Size Guide
What is a Breast Pump Flange?
The flange is the breast pump part that comes in contact with your body when placed onto the breast and nipple, forming a vacuum seal with the areola. It's shaped like a funnel. The flange draws your nipple into the tunnel of the pump where milk is extracted.
Flanges are typically made of plastic or silicone and come in various sizes to accommodate different nipple dimensions.
Some breast pumps come with multiple flange sizes or offer smaller inserts or cushions to customize the fit within the flange. This reduces the opening of the tunnel where the nipple enters and allows for a more comfortable and effective pumping experience.
Why Breast Pump Flange Size Matters?
Whether the shield or flange size of your breast pump is right or not greatly affects your breast comfort and milk output. A properly fitted flange maximizes milk output, prevents nipple damage, and ensures effective milk pumping. If you want to ensure the most amount of milk during your pumping and comfort during and after pumping, measuring your nipple size accurately is very crucial.
Flange sizes typically range from 13 to 36mm, depending on brand. This measurement refers to the beginning of the flange tunnel, not the flange opening. Momcozy breast pumps include a standard 24mm flange and offer additional 27mm flanges for moms with larger nipples. We also provide inserts ranging from 15mm to 21mm to accommodate a variety of nipple sizes.
What Should Your Nipple Look Like in the Flange?
Your nipple should comfortably fit within the flange tunnel without rubbing or pinching. It should fit snugly inside the tunnel of the flange.
If the flange is too small, your nipple might rub against the sides of the flange causing discomfort. If the flange is too large, the areola may be sucked in, which can reduce milk output and cause pain.
Too Small
Nipple rubs against the flange
Correct Fit
Nipple fits snugly inside the tunnel of the flange
Too Large
Nipple along with aerola is being sucked into the flange
How to Measure Your Flange Size: Two Easy Methods
To determine the best flange size for you, you’ll need to measure your nipple first.
Method 1: Use a nipple ruler or a regular ruler.
Step 1: Stimulate your nipple to make it perk up.
Step 2: Hold the ruler perpendicular to your breast, align the 0 mark with the base of your nipple, and make sure the edge of the ruler touches your areola.
Step 3: Measure the distance in millimeters from the base to the top of your nipple — that’s your nipple size.
Method 2: Use a Nipple Ruler with sizing holes
Step 1: Stimulate your nipple to make it perk up.
Step 2: Try inserting your nipple into the sizing holes one by one to find the one that fits comfortably. Your nipple should be able to pass completely through the hole, and the edge of the ruler should touch your areola at the same time.
Step 3: Note the size marked on the hole that fits best — that’s your nipple size.
How to Determine Your Momcozy Wearable Breast Pump Flange Size?
Momcozy includes a handy nipple ruler with holes in the breast pump set to make measuring a breeze. Please note that your left and right nipples may have different sizes, so please measure them both to get the exact size.
We recommend adding 1-3mm to your nipple measurement to determine your ideal flange size. Because nipple size can fluctuate when pumping, choosing a flange 1-3mm larger often provides a more comfortable fit. For personalized guidance, refer to our flange size chart below.
Momcozy Breast Pump Flange Size Chart
| Nipple Measurement | Recommended Size | What I Should Purchase |
|---|---|---|
| 11-13mm | 15mm | 15mm Insert |
| 13-15mm | 17mm | 17mm Insert |
| 15-17mm | 19mm | 19mm Insert |
| 17-20mm | 21mm | 21mm Insert |
| 21-23mm | 24mm | Included, no purchase required |
| 24-26mm | 27mm | 27mm Flange |
| 27-29mm | 30mm | not included in the sale |
| Please stimulate your nipple to make it perk up before measuring the size | ||
Remember, every mom is unique. While a 1–3 mm adjustment works for many, it's essential to pay attention to how your body responds during pumping. It's okay if your nipple touches the side of the flange tunnel, but excessive rubbing or discomfort is not. If you experience any issues, don't hesitate to try a different size.
Signs of a Correct Flange Size
Nipple movement: Your nipple should move in and out freely within the flange tunnel without pain or air gaps.
Areola involvement: Only a small portion of your areola should be drawn into the flange.
Comfort: You should not experience any discomfort or pain during pumping.
Nipple condition: Your nipples should appear healthy without redness, blisters, or cracks after pumping.
Will My Flange Size Change?
Possibly! Your breasts may change between the third trimester and after giving birth. They may also change throughout your breast pumping journey, so it's important to check your flange size regularly.
If you measure your nipples before you begin pumping or before giving birth, be sure to add 1–3 mm to your nipple diameter when choosing the correct flange size. This accounts for the swelling that may occur during pumping.
Need more help? Please feel free to Email Us.