How do I know what size Express Cups will fit me?

The Express Cups come in two size options 24mm and 28mm. You also receive free inserts, when you purchase the 24mm Express cups, you additionally  receive 22mm inserts and when you purchase the 28mm Express cups, you additionally receive 26mm inserts. You can also purchase 19mm inserts separately for the 24mm Express cups, when you need to go even smaller.

To determine you "SIZE", you have to measure your nipple size as follows:

Stimulate your nipple so that it stands up and use a ruler to measure the width (diameter) of the nipple base (don't include the areola).


Nipple sizes:


Breast shield size:

How to purchase:
14 to 16mm 19mm Buy size 24mm flanges, and use with size 19mm convertor (buy separately - Click here to buy)
17 to 19mm 22mm

Buy size 24mm flanges, and use the size 22mm convertors that you receive together with it.

19 to 21mm 24mm

Buy size 24mm flanges

21 to 23mm 26mm

Buy size 28mm flanges, and use the size 26mm convertors that you receive together with it.

23 to 25mm 28mm

Buy size 28mm flanges


If you are currently pregnant consider sizing up a few millimetres as your nipple size can get slightly larger following childbirth.

Finding the best fit breast shield is important for both your comfort and effectiveness of the breast pump. Once you are pumping, if you have any discomfort or concerns about your size we recommend talking to a Lactation Consultant.

If you have any further questions, please email us at