Cycle Regularity Tracker
Assess menstrual cycle regularity, detect patterns, and identify potential concerns from cycle history.
Results
Visualization
How It Works
Cycle regularity is assessed using the coefficient of variation (CV). A CV under 6% indicates regular cycles. Irregular cycles can signal hormonal imbalances, PCOS, or thyroid issues.
The Formula
CV = (Standard Deviation / Mean) × 100%
Normal cycle range: 21-35 days. Normal period: 2-7 days.
Variables
- CV — Coefficient of variation — percentage measure of cycle consistency
- Polymenorrhea — Cycles shorter than 21 days
Worked Example
Cycles of 28, 30, 27, 29, 31, 28: Mean = 28.8, CV = 4.6% — Good regularity.
Practical Tips
- Track at least 6 cycles for a reliable regularity assessment.
- Stress, weight changes, and exercise can temporarily affect cycle regularity.
- PCOS is the most common cause of irregular cycles in reproductive-age women.
- Thyroid disorders (both hypo and hyper) commonly cause menstrual irregularity.
- If cycles are consistently over 35 days, you may not be ovulating every cycle.