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Menstrual cups come in a whole host of sizes because every person’s body is different.

How do you know which one to pick? It can be done with some experimentation. The lowdown on what to consider when choosing a menstrual cup size.

Small and large are the two most common sizes. But you may see small referred to as 1 or A and large called 2 or B.

Some brands have a bigger range of sizes, including ones to suit teens and people with a low cervix.

“The size doesn’t relate to how much liquid the cup can hold but how wide it is.”

No. There’s no standard sizing guide for menstrual cups, with one comparison finding small size diameters ranging from 39 mm to almost 49 mm across brands.

The small size is designed for people under 30 who have no history of having babies.

The larger size is for people over the age of 30 who have a history of giving birth.

Some manufacturers determine cup size by the amount of menstrual flow.

You may have to try a few to find the right fit.

Most brands have a size guide that includes recommendations for your lifestyle.

Popular brands include:

  • Lunette offers model 1 for light to moderate flow and model 2 for moderate to heavy flow.
  • DivaCup offers model 0 for people 18 or under who are new to having a period, model 1 for people between 19 and 30 with a medium flow, and model 2 for people who are over the age of 30 or have a heavier flow.
  • MeLuna offers standard height and shorter cups for low cervixes in four different sizes ranging from teen designs to ones for people who’ve had multiple vaginal births.
  • Lena offers a small size for beginners and people with a low cervix, a large size for experienced users or people with a heavy flow, and an even smaller, softer design for people with sensitive anatomies.
  • Cora offers size 1 for people new to cups or who have a light to medium flow and size 2 for people who’ve given birth or have a medium to heavy flow.
  • Intimina offers a few innovative cups, including one for beginners and one that can be rolled as thin as a tampon to offer comfort for people who have a higher cervix or heavier flow.

When choosing a size, consider all of the below factors.


Some brands prefer not to base cup sizes on age, but you’ll see it mentioned on many sites as it can affect the tightness of pelvic floor muscles.

Smaller sizes are for people under 30 and larger sizes are for people over 30.

Smaller cups are specially designed for teens who are new to having periods.

Birth history

If you have given birth or had a full-term baby, the menstrual cup size can be affected.

Again, this is all about pelvic floor muscles and how pregnancy can weaken them.

“Smaller cups are usually recommended for people who haven’t delivered a child or had a full-term pregnancy, and larger cups are usually more secure for people who have given birth or carried a pregnant woman to full term.”

Cervix height

The length of your vaginal canal is the height of your cervix. It can change throughout your menstrual cycle so you want to know its lowest position.

A cup will sit further up if the cervix is higher. Small cups can be difficult to reach, as you may struggle to get them.

To figure out whether your cervix is high or low, insert your longest finger into your vagina on or just before the first day of your period and feel for your cervix.

It will be at the top of your vaginal canal and should feel similar to the tip of your nose —a smooth raised part with a dimple in the middle.

If you have a high cervix, you probably have a high finger. It is likely low if you reach it at the first knuckle. In between is average.

Overall fitness

Exercise can help relax the muscles of the uterus.

“If you are active, you don’t need the larger size designed for older adults or those who have had a full-term pregnancy or given birth vaginally.”

It is worthwhile to try out different types of firmness as you may find a stiffer cup is better for active days.

Menstrual flow

Flow is something to think about, but not all menstrual cup manufacturers mention it.

A lighter flow —where you’d typically need to change a regular tampon or pad a couple of times a day —usually equates to a smaller menstrual cup.

A heavier flowwhere you’d need to change a highly absorbent tampon or pad every 2 to 3 hours —is often more suited to larger cup sizes.

Cup length

If a cup is too long to fit inside your vaginal canal, it will be uncomfortable.

You can determine the right length by measuring where your cervix is.

Cup diameter

“The cup’s diameter is usually referred to as the menstrual cup sizes. A small cup is smaller than a large cup. Brand diameter sizes can vary.”

The diameter size will be determined by other factors, such as your age and pregnancy history.

Cup capacity

Menstrual cups can hold different amounts of fluid.

Smaller ones can hold 25 to 27 liters while larger ones can hold 30 liters.

Unless you have a heavy flow, the capacity is not an important factor.

Do certain factors matter more than others?

Ensuring your menstrual cup is wide enough to fit inside your body is the most important.

It means focusing on your birth history, rather than your menstrual flow.

You should be able to remove your cup without much trouble once you have had a few practice sessions. It should feel good once it is in.

If your cup is too small, you may notice leaks and may find it difficult to reach for removal.

If it is too big, you may not be able to insert it as far in as you need to.

Are menstrual cups uncomfortable?

A menstrual cup should feel similar to a tampon —you know it’s there but it’s not uncomfortable.

If the cup is too big for your body, too firm, or you attempt to remove it without first breaking the seal by pinching the base, you will not experience any pain.

But if you’re feeling pain or discomfort when using the right size menstrual cup, consult with a healthcare professional. There may be an underlying condition causing pain, such as vaginismus.

Can you use a menstrual cup if you have severe cramps?

Menstrual cramps originate in the uterus, which isn’t where the menstrual cup sits. That means it’s unlikely they cause cramps.

Already having severe cramps shouldn’t be a barrier either —people with painful periods and conditions like endometriosis and PCOS do use menstrual cups.

Some people have found cups to help their cramps, while others have found cups that make them worse.

There is no evidence to support either of these findings.

Will wearing a menstrual cup affect how you use the bathroom?

You can use a menstrual cup in the bathroom.

“It sits in the vaginal canal so won’t block any movements.”

The menstrual cup may be pushed down the vaginal canal. It is a good idea to make sure it is still in place when you are done.

Are there any risks to wearing the wrong size menstrual cup?

Most sizing issues come with minor risks, such as irritation and leakage.

But there is a chance of bigger risks, both with a cup that’s too small or too big.

If your cup is too small, it can cause pain or even cause a hernia when removed.

The urine can be blocked by a cup that is too big.

It may take a few tries to find the right cup. It can be hard to find the best fit for your body without some experimentation, because all brands have different sizes.

If the cup is not the right fit, some brands will allow you to get your money back. Start with age and birth history and then move on.

Lauren Sharkey is a U.K.-based journalist and author specializing in women’s issues. When she isn’t trying to discover a way to banish migraines, she can be found uncovering the answers to your lurking health questions. She has also written a book profiling young female activists across the globe and is currently building a community of such resisters. Catch her on Twitter.