Estimate your ovulation date and fertile window. Enter your last period date and cycle length to plan around your most fertile days.
This calculator provides estimates based on average cycle patterns. Actual ovulation can vary by several days. For more accuracy, combine with basal body temperature tracking and ovulation predictor kits (OPKs).
The fertile window is the approximately 6-day period when conception is possible — the 5 days before ovulation and the day of ovulation itself. Sperm can survive up to 5 days in the reproductive tract, while an egg is viable for about 12–24 hours.
Yes. In a 28-day cycle, ovulation typically occurs on day 14. In a 35-day cycle, it would occur around day 21. The luteal phase (after ovulation) is usually consistent at about 14 days.