Ovulation & Fertility Window Calculator

Enter your last period start date and average cycle length to estimate your next ovulation day and fertile window.

Cycle Details
Notes:
  • Ovulation typically occurs ~14 days before the next period.
  • Fertile window spans ovulation day ± 2 days.
  • This is an estimate and not medical advice.
Results
Estimated Ovulation
—
Fertile Window: —
Upcoming Cycles

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