Estimate your most fertile days based on menstrual cycle length. This tool is designed for educational and planning purposes only.
The fertility window is the time during a menstrual cycle when pregnancy is most likely. It typically includes the five days before ovulation and the day of ovulation itself.
Ovulation is estimated as:
Ovulation Day = Cycle Length − 14
Fertile window includes:
Ovulation Day − 5 through Ovulation Day
⚠ This calculator provides estimates only and does not replace medical advice.