Ovulation Calendar Tracker
Enter the first day of your last period and your average cycle length. The tracker estimates your ovulation day, fertile window and next period, and shows them on a colored monthly calendar.
Disclaimer: these are estimates only and not medical advice. Real cycles vary. See a doctor for family planning and fertility questions.
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Frequently asked questions
Ovulation is estimated as the first day of your last period plus your average cycle length minus 14 days. For a 28-day cycle this places ovulation about 14 days after the period starts.
The fertile window is shown as the 5 days before the estimated ovulation day plus ovulation day and the day after, giving 7 highlighted days in total on the calendar.
Use the Previous and Next buttons above the calendar to move month by month. The colored marks for period, fertile and ovulation days are recalculated for every month you view.
No. These are simple estimates only and not medical advice. Real cycles vary from month to month, so always see a doctor for family planning and fertility questions.