Which menstrual cup size is right for me?

Which Menstrual cup size is right for me-min

Choosing the right menstrual cup size is like finding a shoe that fits perfectly. Before buying, you’ll know your size and which shape fits you comfortably. The same rule applies for menstrual cups, though unfortunately, you can’t just go into a store and try them until you find one that works well for you.

Also, each vagina is anatomically unique, so there is no such thing as ‘one size fits all’. That’s why we have a 120 day “no questions asked” money back guarantee. Try a Ruby Cup and if within 4 calendar months from your order you don’t really feel that it fits, you can either exchange the size or get a full refund.

Luckily, there are many different shapes and sizes of menstrual cups, which makes it possible for you to find the perfect fit.

To prevent you from having to order many different brands before finding your “Goldilocks” cup, we advise that you know your flow and your anatomy before choosing a menstrual cup.

Here are the two key factors to look out for when choosing the right size:

  • Heaviness of your menstrual flow
  • Position of your cervix

Once you know these two characteristics you can narrow down your pool of potential menstrual cups. Ruby Cup is a great starter cup and works well for the majority of users. If you’re not sure about the height of your cervix, definitely read this guide to help you figure that out.

Ruby Cup is available in two sizes, small and medium. We recommend Ruby Cup Small if you have a light to medium flow and Ruby Cup Medium if you have a medium to heavy flow. These are the measurements of Ruby Cup:

Ruby Cup Small

For light to medium flow

Cup LengthStem LengthTotal LengthDiameterCapacity to the RimCapacity to the holes
46 mm19 mm65 mm40 mm24 ml19 ml


Ruby Cup Medium

For medium to heavy flow

Cup LengthStem LengthTotal LengthDiameterCapacity to the RimCapacity to the holes
51 mm17 mm68 mm45 mm34 ml24 ml


If you have a low cervix, try Ruby Cup Small as it is shorter. Also a good menstrual cup hack is to simply trim the stem if it’s too long.

Still in doubt? Our Recommendation

Ruby Cup Sisterpack

If you are still in doubt, remember that both cups can work for you. If you have a heavy flow but want to use a Ruby Cup Small because of your low cervix, you would only need to empty it more frequently.

If you have a light flow it is no problem at all to use Ruby Cup Medium, it’s greater capacity will simply hold more than the Ruby Cup Small and not be full when emptied.

If you have a low cervix, but want to use Ruby Cup Medium, you can just trim the stem to make it sit comfortably below your cervix.

We currently offer Ruby Cup Small and Medium as a Ruby Cup Sisterpack with a discount in our shop.

Do age or childbirth influence the menstrual cup size needed?

We do not recommend that you choose your menstrual cup based on whether you have given birth or not or your age. Since each body is anatomically unique, these are not very reliable factors.  We have received a lot of feedback from users who, after they have given birth, suddenly needed a Ruby Cup Small instead of a Ruby Cup Medium and vice versa.

So keep in mind that giving birth does not necessarily mean that you now need a bigger menstrual cup. Your flow and cervix position are better indicators in our experience.

Try Ruby Cup with no strings attached

Every Ruby Cup comes with a life-changing Buy One, Give One cup donation and a 100% Money Back Guarantee. Switch size or get a full refund within 120 days, no questions asked.