Ovulation Calculator

Ovulation typically occurs 14 days before your next period, regardless of cycle length. In a 28-day cycle, that's day 14. In a 32-day cycle, it's day 18. This is why cycle length affects ovulation timing but the luteal phase (ovulation to period) stays ~14 days.

The fertile window spans 5 days before ovulation plus the day of ovulation — 6 days total. Sperm can survive up to 5 days inside the female reproductive tract, while an egg is viable for only 12–24 hours after ovulation. The highest probability of conception is the 2 days before and the day of ovulation.

This calculator assumes regular cycles. Irregular cycles, stress, illness, hormonal conditions (PCOS), or recent hormonal contraceptive use can shift ovulation timing significantly. For precise ovulation detection, use basal body temperature (BBT) charting or LH ovulation predictor kits (OPKs).