Ovulation Calculator
Estimate your ovulation date, fertile window and next period from the first day of your last period and cycle length.
Enter your values and press Calculate.
How to use the Ovulation calculator
This is an estimate only and must not be used as contraception. Ovulation tests and cycle tracking give better accuracy.
Formula
Ovulation usually happens about 14 days before the next period. The fertile window is the 5 days before ovulation plus the day of ovulation.
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