Fitting Guide

Why is it important to measure?

Having the correct size breast shield or flange while pumping is crucial for both comfort and milk output. Using the incorrect flange size can also result in discomfort, pain or reduced output. Use our measuring guide to make sure you get the right size and you're make the most of your pumping sessions.

The nipple diameter is actually the most important part to get your pump fitting comfortably and correctly. Our standard size 24mm pumps fit a lot of Mums, but make sure to follow the guide before ordering your pump just in case you need to order a different size flange.

Our pumps are suitable for breasts of all sizes! Just make sure you're wearing a supportive bra to hold the pump firmly against your breasts, you've measured and your using the correct flange size, and the pump will work for you. 

Find your correct size

Step 1

If you are measuring POSTPARTUM:

Measure BEFORE a pumping/ feeding session. If you're currently pregnant

Stimulate your nipple to make it perk up. This will help replicate the size of your nipple when pumping.

Then, proceed to step 2

If you are currently PREGNANT:

To ensure you have your breast pump ready when you need it, we recommend buying now in the standard 24mm size to be prepared.

Around 2-3 weeks before your due date, you can take the most accurate measurement before your baby is born. If you need flange inserts, you can easily order the right flange insert size from our website.

When you're ready to do your measurement while pregnant - Stimulate your nipple to make it perk up. This will help replicate the size of your nipple when you start pumping once baby is born. Then, proceed to step 2

Step 2

Using a ruler, measure your nipple from bottom to top to where your nipple meets the areola (see diagram provided).

Measure only the nipple, excluding the areola, which is the outer edge surrounding your nipple. Express the measurement in millimeters, where 1cm is equivalent to 10mm.

Step 3

Get the measurement of both nipples (yes the left and right can each be different!) and the size measurement is done.

Please remember that nipple size changes are common throughout pregnancy and postpartum due to hormone fluctuations. Most commonly mums experience a change in size at 8-12 weeks postpartum, so please ensure to remeasure around this time to maximise milk output and comfort.

What size do I need?

Find your correct size in the table. The flange needs to have the correct amount of room to allow for movement of the nipple within the tunnel whilst pumping - in the table above we've accounted for this in our recommendations.

The Night Owl pumps come either with either 24mm or 27mm shields.

For smaller sizes we have 13mm, 15mm, 17mm, 19mm or 21mm flange inserts available. To see how these work head over to our how to guide.

Please note the flange inserts are only compatible with the 24mm shields.

You can view our full range of accessories here!

How do I know if my flange size is correct?

Need more help? Head over the our contact us page and we'd be happy to answer any questions you ay have!