Are you wondering when to measure your nipple size for a breast pump? You’re not alone! Nipple size can change during pregnancy, postpartum, and breastfeeding, making it tricky to get the right fit.

Measuring too early or too late can lead to discomfort and less effective pumping sessions—but we’re here to help. 

In this guide, we’ll cover the best time to measure your nipple size based on the different stages of motherhood. By the end, you’ll know exactly when to take accurate measurements for a comfortable and efficient pumping experience. 

Let’s get started!

The best time to measure your nipple size for a breast pump flange is subjective and can vary for each mother. However, some general guidelines can help determine the most appropriate time.

If you plan to pump after giving birth, it can be helpful to measure your nipple size toward the end of your pregnancy. However, keep in mind that nipple size can change postpartum due to milk flow and swelling.

Use this measurement as a rough starting point for choosing a flange size, but consider measuring again after delivery.

Once your milk “comes in” (usually 3-5 days postpartum), your breast size and nipple size may temporarily increase due to fullness or engorgement. This is a good time to measure, as it will give you a more accurate idea of your postpartum nipple size.

After the early postpartum adjustments, your nipple size may stabilize slightly as engorgement decreases. Measuring around this time can help you find the most accurate flange fit for regular pumping sessions.

If pumping feels uncomfortable or you’re not getting much milk, it’s worth remeasuring your nipple size. Your nipple size can change during your breastfeeding or pumping journey.

If you move from occasional to more frequent pumping, re-check your fit. Long-term pumping can sometimes alter nipple size, requiring adjustments to flange size.

It’s generally recommended to measure your nipples before pumping. Measuring before a pumping session gives you a more accurate idea of your nipple size in its natural state without any temporary changes caused by pumping. Pumping can cause swelling, which might make your nipples appear larger, potentially leading to incorrect flange size selection. 

However, if you’ve already been pumping and notice discomfort or an improper fit, you can still measure your nipples after pumping. Just keep in mind that the size you measure post-pumping might not reflect your actual resting nipple size. 

Consistency matters to ensure the best fit. Try measuring multiple times before and after pumping to look for patterns. That way, you can make a more informed choice about the flange size that will provide optimal comfort and efficiency for your needs.

Measuring your nipple size is straightforward and can be done at home. Here’s how:

1. Gather What You Need: You’ll need a ruler or a soft measuring tape with millimetre markings.
2. Find the Diameter: Measure the width of your nipple at its base (where it meets the areola) when your nipple is its most natural size. Make sure you only measure the nipple itself, not the areola.
3. Choose the Right Flange Size: Add approximately 2-4 millimetres to your nipple measurement to determine the correct flange size. This additional space allows your nipple to move freely within the flange tunnel during pumping without rubbing against the sides.

For example, if your nipple measures 17 mm in diameter, you might need a 19 mm or 21 mm flange.

Adjust If Needed: If the flange feels too tight or too loose (e.g., excessive areola pulling or nipple rubbing), try a different size. Breast pump manufacturers often have flange sizing guides to help.

In summary, there is no one perfect time to measure nipple size for a breast pump flange, as it can vary depending on individual circumstances.

However, some general guidelines suggest measuring toward the end of pregnancy or during early postpartum and then reassessing as needed throughout the breastfeeding journey.

Measuring before pumping is generally recommended for the most accurate results, but measuring after pumping can also provide helpful information. 

Remember to choose a flange size that allows room for your nipple to move comfortably during pumping and adjust as needed.