About the Ovulation Calculator
Ovulation is when an ovary releases an egg, and the days around it — your fertile window — are when conception is most likely. For a typical cycle, ovulation occurs roughly 14 days before the next period starts, though this shifts with cycle length.
This calculator uses the first day of your last period and your average cycle length to estimate your ovulation date, your most fertile days, and an approximate due date if conception occurs. Cycles vary from month to month and person to person, so use the result as a helpful guide for planning rather than a precise medical prediction.