Menstrual Cycle Variability Calculator
Track your cycle lengths to understand your hormonal health.
Enter Your Cycle Lengths
Your Results
Variability
4 days
Average Length
29.0 days
Normal Variability
Your cycle length variability is within the typical range. This suggests regular ovulation.
Cycle Length Visualization
28
30
27
31
29
Why Cycle Variability Matters
Your menstrual cycle is a key indicator of your overall health. While a perfect 28-day cycle is a myth for most people, a relatively consistent cycle length is a sign of regular ovulation and balanced hormones. Variability is the difference between your shortest and longest cycle.
A small amount of variability (e.g., up to 7 days) is considered normal. High variability can sometimes be a sign of stress, travel, dietary changes, or underlying health conditions like Polycystic Ovary Syndrome (PCOS) or thyroid issues. Tracking your cycle variability can empower you to have more informed conversations with your doctor.