How to Choose the Right Menstrual Disc Size: Sizing Guide 2025 Choosing the right menstrual disc size is the key to comfort, leak-free performance, and confidence. This comprehensive sizing guide helps you pick the perfect disc based on anatomy, flow, and lifestyle.
📏 Key Factors That Affect Sizing 1) Cervix Height •
Low cervix: Choose shallower, softer discs or smaller diameter •
Medium cervix: Most standard discs fit well •
High cervix: Larger diameter or firmer rim helps placement
How to measure: • Insert a clean finger and feel for the cervix (round, firm, like a nose) • Note how deep your finger goes: knuckle 1 = low, 2 = medium, 3 = high
2) Flow Volume •
Light to medium: 30–50 ml capacity is enough •
Heavy: 50–70 ml capacity recommended •
Very heavy: 70–80 ml (or use higher-capacity brands)
3) Pelvic Floor Tone •
Strong tone (athletes, heavy lifters): Slightly firmer rim improves seal •
Sensitive/soft tone: Softer discs improve comfort
4) Birth & Anatomy History •
No vaginal births: Standard sizes often fit best •
Postpartum: Consider larger diameter or firmer rim for seal
📊 Sizing Recommendations by Profile | Profile | Recommended Disc | Why |
| Beginner, medium cervix | Flex Disc (disposable) | Easy insert, universal fit |
| Eco-first, medium/high cervix | Nixit (reusable) | Soft, one-size, comfy |
| Heavy flow, high-impact | Cora Disc (reusable) | Firmer rim + 60 ml |
| Low cervix, sensitive | Shallow, soft disc | Less pressure, easier fit |
| Unsure, wants removal aid | Lumma Disc (string) | String helps removal |
📐 Diameter vs Capacity •
Diameter affects how the rim tucks behind the pubic bone •
Capacity affects wear time on heavy days • For leaks with correct placement → try
larger diameter • For frequent emptying → try
higher capacity 🧪 At-Home Fit Test (3-Day Protocol) Day 1 (Light day): 1. Insert at home, walk, sit, squat 2. If you feel the rim → size may be off or placement shallow
Day 2 (Moderate): 1. Wear 6–8 hours 2. If leaks without overflow → diameter too small or rim too soft
Day 3 (Heavy): 1. Track empty intervals 2. If <6h on heavy days → increase capacity
🧭 Brand Shortlist by Need •
Maximum capacity: Cora Disc (~60 ml) •
Softest feel: Nixit •
Beginner-proof: Flex Disc (disposable) •
Easiest removal: Lumma (with string) •
Budget / multiple sizes: Lumma (S/M/L)
🧩 Troubleshooting Sizing Issue: Leaks despite correct placement • Size up diameter or choose firmer rim (Cora)
Issue: Pressure/discomfort • Size down diameter or switch to softer rim (Nixit)
Issue: Hard to reach on removal • Try smaller diameter or disc with string (Lumma)
Issue: Frequent overflow on heavy days • Increase capacity (50–70+ ml)
❓ FAQ Q: Do one-size discs really fit all? A: They fit many, but not all. Use the 3-day fit test to confirm.
Q: Low cervix with heavy flow — what should I choose? A: Softer, slightly smaller diameter plus higher capacity, or plan more frequent emptying.
Q: Active lifestyle and strong pelvic floor — what should I choose? A: A firmer-rim disc (e.g., Cora) to maintain a reliable seal during impact.
Not sure about your size? Share height/weight, cervix height (low/medium/high), flow intensity, and goals — the community will recommend a precise fit.
