Menstrual Cycle Length Tracker — Formel

Menstrual Cycle Phases

Typical 28-Day Cycle

PhaseDaysDescription Menstruation1-5Period bleeding Follicular1-13Follicle development Ovulation~14Egg release Luteal15-28Post-ovulation PMS Window~21-28Premenstrual symptoms

Next Period = Cycle Length - Days Since Last Period Ovulation Day = Cycle Length - 14

Lösungsbeispiel

A 28-day cycle, period lasts 5 days, currently on day 15.

  1. Next period in = 28 - 15 = 13 days
  2. Ovulation day = 28 - 14 = Day 14 (just passed)
  3. PMS window starts = Day 21 (in 6 days)