Ovulation Calculator
Enter the first day of your last period and your usual cycle length to see your most fertile days for the next few cycles.
Frequently asked questions
When do I ovulate?
Usually about 14 days before your next period: day 14 of a 28-day cycle, or day 21 of a 35-day cycle.
Which days are the most fertile?
The five days before ovulation, the day itself and the day after. Sperm can survive up to five days, while the egg lives about a day.