How to Measure Your Cervical Position and Why It Matters for Menstrual Cup or Disc Choice

Understanding your cervical position is crucial for finding a comfortable, leak-free menstrual cup or disc. This is often referred to as finding your "goldilocks cup" - the one that fits just right!

This guide explains how to measure your cervical position using the knuckle test, why it matters and recommends products for different cervix heights.

What Is Cervical Position, and Why Should You Care?

Your cervix is the lower part of your uterus that sits at the top of your vaginal canal. Its position isn’t static—it fluctuates during your cycle and a cup or disc that doesn’t match your unique cervical height may cause troubles: cups can sit too high or too low, lead to leaks or even cause discomfort.

Key reason to measure your cervix are to;

1. Avoid discomfort: A cup that’s too long may press against a low cervix or be pushed low and cause irritation or even expelled.
2. Ease of removal: High cervixes may require longer cups and/or stems so they are easier to reach when being removed.
3. Prevent leaks: A well-fitted cup creates a seal around (not inside) the cervix. Misplacement due to incorrect sizing can cause leaks.
4. Saves time and money: Measuring your cervix narrows down the product options that are likely to be a good fit for your anatomy and eliminates those that aren't suitable.   

How to Measure Your Cervical Position: The Knuckle Test

1. Timing: Measure during your period when the cervix is lowest.
2. Preparation: Wash hands and assume a comfortable position (squatting, sitting, or one leg raised).
3. Insert a finger: Gently insert your index finger into the vagina until you feel the cervix (it resembles the tip of your nose).
4. Knuckle rule: Note how many finger segments (knuckles) fit before touching the cervix:

Low cervix: The cervix is immediately at the vaginal opening or between knuckles 1-2 (≤44mm).

Medium cervix. You can insert your finger between 2–3 knuckles before felling the cervix (45–55mm).

High cervix: You need to insert your whole finger  to feel your cervix or can't reach it at all (≥55mm).

Jot down your result. You can repeat this measurement on different days of your period, as your cervix can shift slightly.

Tips for Measuring Accurately

• Relax your pelvic muscles.
• Avoid testing immediately after penetrative sex; the cervix position can temporarily change.
• Using the same finger each time helps consistency.

Choosing a Menstrual Cup or Disc Based on Your Cervix Position

Armed with your measurements, you can now make a informed choice. Here’s how to use your cervical position knowledge when shopping.

Cups and Discs for a Low Cervix

A low cervix means a short vaginal canal. Most menstrual discs are suitable for a low cervix as they have a flat-fit design. Standard or long cups may press uncomfortably or even protrude. Look for:

• Shorter cups or discs, labelled for low cervix.
• Smaller capacities, as longer designs may not fit.
• Lower rims, for ease of insertion and removal.

Suggestions: Merula OS, Hello Low Cervix and most menstrual discs as they have a flatter fit design that sits high on the fornix. 

What to Choose for a Medium Cervix

Most average cups and discs will suit, but pay attention to:

• Stem length: Some remove more easily if they have a moderate stem.
• Capacity: Choose based on your flow, not just length.

Suggestions: Saalt, Lunette and AllMatters.

Best Choices for a High Cervix

A high cervix means menstrual discs may be difficult for you to reach in they don't have a "tail" or finger-loop. In terms of cups, you’ll do well with:

• Longer cups or larger discs, which sit higher.
• Stems: A longer stem helps with removal.
• Comfort features: Flexible bodies are easier to locate and remove.

Suggestions: Lily Cup, Diva Cup and the Hello High Cervix Cup

Additional Considerations: Shape, Firmness, and Capacity

While cervical position is crucial, it’s not the only factor. For personalised comfort:

• Cups or discs for tilted/retroverted uterus: Some shapes hug the cervix better.
• Firmness: Softer cups are comfier but require strong pelvic muscles; firmer ones pop open more easily.
• Flow and capacity: Heavier flow calls for higher capacity, but length must always suit your cervix position.

If in doubt, consult online sizing guides or product-specific customer service.

Troubleshooting: Common Cervix Position Issues with Cups or Discs

Even with the right measurements, some users experience issues. Here’s what might crop up:

• Leaking: The most common cause is the cup sitting beside or under the cervix, not beneath it. Double-check your insertion technique.
• Difficulty removing: With a high cervix, relax and bear down gently. With a low cervix, trim the stem if it protrudes.
• Discomfort or pressure: Often the cup is too long or wide for a low cervix. Switching to a shorter or narrower cup usually resolves this.
• Cup migration: Sometimes a cup slides up during the day—normal for a high cervix, but persistent issues may warrant a longer cup.

Listen to your body and adjust size or brand as needed.

FAQs on Cervix Position and Menstrual Cups

Can my cervix position change over time?
Yes! Pregnancy, childbirth, and age can shift cervical height. Re-check periodically if you notice changes in comfort or fit.

What if I can’t locate my cervix?
Try again at different points in your cycle or during your period. If you still struggle, opt for adjustable cups or those recommended for various cervix heights.

Is a disc or a cup better for a high or low cervix?
Both work; just ensure you select the correct model for your measurements.

Does cervical position affect period leaks only with cups?
No; it can influence tampon fit too. But because cups and discs rely on anatomical fit more, measurement is essential.

Knowing your cervix position is the foundation for choosing a menstrual cup or disc that feels tailor-made for you. A simple self-check leads to better comfort and leak protection—time to get measuring and enjoy stress-free periods!