Important: This ovulation calculator provides estimates based on standard menstrual cycle patterns. It is NOT a substitute for medical advice, a fertility treatment, or a form of birth control. Fertility varies significantly between individuals and cycles, and calendar-based predictions can be wrong. Consult a healthcare provider for personalized fertility guidance.
Enter the first day of bleeding from your most recent menstrual period.
Typical range 21–45 days. Default is 28.
Advanced Options
The number of days between ovulation and your next period. Typical luteal phase is 12–14 days.
Estimated Ovulation Date
Two most fertile days:
Fertile Window (6 days)
Next Expected Period
Implantation Window
Earliest Pregnancy Test
Cycle Calendar
Menstruation
Follicular
Fertile Window
Ovulation
Luteal
Reminder: This ovulation calculator provides estimates based on standard menstrual cycle patterns. It is NOT a substitute for medical advice, a fertility treatment, or a form of birth control. Ovulation can shift unpredictably due to stress, illness, travel, medication, PCOS, perimenopause, or other conditions. Sperm can survive up to 5 days in the female reproductive tract, which means pregnancy is possible outside the predicted fertile window. For reliable contraception or personalized fertility guidance, consult a qualified healthcare provider.