Which Menstrual Cup Size Is Right For Me?

Everybody’s body is unique. So, when it comes to questions around menstrual cup sizing, we need to start the conversation with you – your body and your periods.

This way, we can help you find out which size of menstrual cup is best designed to meet your needs and which size will best help you manage your menstrual flow.

In this article, we’ll explain how to choose the right menstrual cup size for you. And we’ve also made a video, which is ideal for beginners, where you can see what a Ruby Cup menstrual cup looks like – and hear how to choose the right size for you and your period:

How big is a menstrual cup?

If you haven’t seen a menstrual cup before, at Ruby Cup we have two menstrual cup sizes – small and medium. And they’re made to fit every body. 

Both cup sizes are made from soft, medical grade silicone and are designed to be easy to use and comfortable to wear.

The Ruby Cup menstrual cup size chart

menstrual cup sizing charts can help you choose

Ruby Cup’s menstrual cup measurements are:

  • Small (our smallest menstrual cup) is 65mm high and 40mm wide.
  • Medium (our largest menstrual cup) is 68mm high and 45 mm wide.

What size menstrual cup should I get?

When it comes to working out which of our soft cup sizes will work for you, we start by helping you find out how your body is actually shaped, both inside and out.

That’s because there are two factors to consider when you’re working out which size Ruby Cup will work for you.

1-How heavy is your menstrual flow?

The first thing to consider is how much blood you lose when you have your period. We call this your menstrual flow and it can be light or it can be heavy.

Light flow?
If you have a light menstrual flow, you may be using small or regular tampons and slim pantyliners or pads. You’re likely to be changing your period product a few times during the day.

Heavy flow?
If you have a heavy menstrual flow, you’re likely to be using super or super plus size tampons and maxi pads. You’re also likely to be changing your period product frequently during the day and also at night.

2. Do you have a low cervix – or a high cervix?

How to find your cervix

To find your cervix, you’ll need to slide your longest finger into your vagina.

You can do this while you’re lying down, or with one leg up on the side of the bath or the toilet lid. You can also do this whether or not you have your period.

We recommend that you wash your hands well first and try to relax. Then carefully slide your longest finger into your vagina.

What does a cervix feel like?

You’ll find your cervix sitting at the top of your vagina. It’s likely to be at the top of your front vaginal wall – closer to your belly button than to your spine.

To the touch, it will feel like a smooth round, raised circle with a dimple in the middle – a bit like the tip of your nose.

Do you have a high cervix?

If your longest finger goes almost all the way into your vagina before it reaches your cervix you have a high cervix.

Do you have a low cervix?

If your longest finger finds your cervix around the middle knuckle mark, then you have a low cervix.

how to measure cervix for menstrual cup


How to know what size menstrual cup to use? – a simple Ruby Cup guide to  menstrual cup sizing

This simple guide will help you to match your menstrual flow and the position of your cervix to the size of Ruby Cup that will work for you.

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how to choose the menstrual cup size


guide chart choose right menstrual cup size


What if I order the wrong size?

We want you to experience the difference we know a menstrual cup makes, so we offer a no questions asked 120-day money-back guarantee.

“I have to say that I gave a lot of thought before switching to Ruby Cup from the conventional tampons and pads. I wasn’t sure about the physics of it and doubted about how comfortable I would feel. Such a waste of time! I love the product. I’ve only started using it, but I can easily say that it’s one of the best purchases I’ve made.” -Percem


Our 100% money-back guarantee not only gives you time to get used to using your new cup, but if you think you need to order a different size, we’ll exchange it for you – or give you your money back – with pleasure.


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“I bought a Ruby Cup three years ago and I'm never switching back to tampons. The first period with the cup getting it in and positioned right was a bit of a challenge but it's fairly easy to learn. By now I don't even have to think about it anymore. It works just as I hoped it would and I'm very happy with it.” -Marina

“I switched to a cup two years ago and can safely say I'm never going back! It's the best period-based decision I ever made! So easy to use and the freedom it gives is incredible.” -Alice

Periods are universal. Access to menstrual products and period care is not

Ruby Cup was the first menstrual cup company to offer a built-in Buy One, Give One promise on every single cup that we sell. According to Plan UK, around 1 in 10 women globally have been unable to afford protection for their period at some stage in their lives.

When you buy a Ruby Cup, not only do you change your own experience of having your period every month – you can transform someone else’s experience too.

How does Buy One, Give One work?

For every cup sold, Ruby Cup donates another to someone who doesn’t have access to period products.

To date, our customers have helped us to donate 85,000+ Ruby Cups and hold educational programmes for women and girls in 13 countries across three continents, to help them manage their periods safely and effectively.

Today, over 200K people with periods around the world use a Ruby Cup – are you ready to join them?

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Date last reviewed: September 2020