How to know the correct size of a menstrual cup?

Choosing the right menstrual cup size is crucial for comfort, leak prevention, and a positive experience. With so many brands and sizes available, it can feel overwhelming. This guide will help you understand how to pick the perfect cup size based on your body, flow, and lifestyle.

Why Does Size Matter?

A menstrual cup that’s too large can cause discomfort or pressure, while a cup that’s too small may leak or be difficult to remove. The right size fits snugly against your vaginal walls, creates a good seal, and feels comfortable throughout the day.

Factors to Consider When Choosing Your Menstrual Cup Size

1. Age

  • People under 30 typically use smaller or size 1 cups.

  • Over 30 or post-childbirth people usually choose larger or size 2 cups.

2. Whether You’ve Given Birth Vaginally

  • If you’ve had one or more vaginal births, you may need a larger, more flexible cup.

  • If you’ve had a cesarean or no births, a smaller cup might be suitable.

3. Flow Intensity

  • Light to Medium Flow: Smaller capacity cups (around 15-25 ml).

  • Heavy Flow: Larger capacity cups (over 30 ml) reduce the frequency of emptying.

4. Cervix Height

  • Low cervix: Choose a shorter cup (40 mm or less) to avoid discomfort.

  • High cervix: A longer cup (45 mm or more) ensures a good fit.

You can check your cervix height during your period by inserting a clean finger and measuring how far it is from the vaginal opening.

5. Pelvic Floor Strength

  • If you have a strong pelvic floor, firmer cups may work better.

  • If you have a weaker or sensitive pelvic floor, softer cups and smaller sizes tend to be more comfortable.

How to Measure Your Cervix Height at Home

  1. Wash your hands thoroughly.

  2. During your period, insert your middle or index finger into your vagina.

  3. Feel for the cervix—a round, firm, doughnut-shaped bump.

  4. Measure how far your fingertip reaches to the cervix in centimeters or inches.

  5. Compare to cup length recommendations when choosing.

When to Consider a Smaller Size

  • You’re under 30 years old.

  • You have not given birth vaginally.

  • You have a low cervix.

  • You have a light menstrual flow.

  • You have a sensitive or weak pelvic floor.

When to Consider a Larger Size

  • You’re over 30 years old.

  • You’ve had one or more vaginal births.

  • You have a medium to heavy flow.

  • You have a high cervix.

  • You have a strong pelvic floor.

Tips for Finding the Perfect Fit

  • Start with size recommendations but be open to trying a different size or brand if needed.

  • Consider buying a starter kit with multiple sizes if you’re unsure.

  • Check the return policy—some companies offer size exchanges.

  • Practice inserting and removing to get comfortable with your chosen size.

Popular Brand Size Guides (Examples)

Brand Size 1 (Small) Size 2 (Large)
DivaCup Under 30, no vaginal births Over 30 or vaginal births
Lunette Shorter length, smaller capacity Longer length, higher capacity
Saalt Light flow, smaller size Heavy flow, larger size

Choosing the correct menstrual cup size enhances comfort, confidence, and effectiveness. By considering your age, childbirth history, flow, cervix height, and pelvic floor strength, you can find a cup that fits just right.

Personalized Menstrual Cup Recommendations Based on Your Flow and Anatomy

Step 1: Identify Your Flow

  • Light Flow: You bleed lightly, maybe spotting or changing protection every 4-6 hours.

  • Medium Flow: Moderate bleeding requiring changes every 3-5 hours.

  • Heavy Flow: Heavy bleeding with frequent changes, every 1-3 hours on your heaviest days.

Step 2: Know Your Cervix Height

  • Low cervix: You can feel your cervix just inside the vaginal opening or up to 4.5 cm (about 1.75 inches).

  • Medium cervix: Cervix sits roughly 4.5-7.5 cm (1.75-3 inches) inside.

  • High cervix: Cervix is more than 7.5 cm (3 inches) inside.

Step 3: Consider Age and Childbirth History

  • Under 30 years old and no vaginal births? Smaller cup usually fits best.

  • Over 30 or vaginal births? Larger cup recommended.

  • Cesarean births? Smaller or medium cups often work well, as pelvic floor muscles may be stronger.

Personalized Recommendations

Flow & Anatomy Recommended Size & Type Suggested Brands
Light flow + low cervix + under 30 + no births Small, soft, short cup (15-20 ml capacity) Saalt Soft Small, Lunette Size 1, DivaCup 1
Medium flow + medium cervix + under 30 or no births Medium size cup (20-30 ml capacity), moderate firmness Lunette Size 1 or 2, Saalt Regular, DivaCup 1/2
Heavy flow + medium/high cervix + over 30 or vaginal births Larger, firmer cup (30+ ml capacity), longer length DivaCup 2, Lunette Size 2, Mooncup Large
Heavy flow + low cervix + sensitive pelvic floor Small but higher capacity soft cup Saalt Soft Small, Cora Cup Small

Additional Tips

  • If you have a sensitive pelvic floor or discomfort with insertion, try a softer silicone cup.

  • For very active lifestyles, firmer cups provide better suction and stay in place.

  • Always measure your cervix height during your period for best sizing.

  • If unsure, some brands offer starter kits with multiple sizes.

Where to Buy

You can explore a great selection of menstrual cups here:
NYX Period Cup Collection — They offer various sizes and styles to suit different needs.

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