Ovulation Calculator

Ovulation is the release of a mature egg from the ovary. It typically occurs once per menstrual cycle and marks the most fertile period. Understanding ovulation timing is key for both planning and preventing pregnancy. The fertile window: An egg survives 12–24 hours after release. However, sperm can survive in the reproductive tract for up to 5 days. This means the fertile window is approximately 5–6 days: the 5 days before ovulation and the day of ovulation itself. When does ovulation occur? For a standard 28-day cycle, ovulation typically occurs around day 14. However, cycle length varies significantly — for a 30-day cycle, ovulation is around day 16; for a 24-day cycle, around day 10. This calculator estimates based on your cycle length. Signs of ovulation: Slight rise in basal body temperature (BBT) after ovulation, changes in cervical mucus (becomes clear and stretchy, like raw egg whites), mild pelvic pain (mittelschmerz), and a positive ovulation predictor kit (OPK) test. Important note: These calculations are estimates based on average cycle patterns. Stress, illness, travel, and other factors can shift ovulation timing. For medical fertility concerns, consult a healthcare professional.