Ovulation Calculator

This calculator helps you predict your most fertile days of the month. Menstrual periods vary from woman to woman and month to month. Use this calculator to help determine the timing of your ovulation and peak fertility. Use our dropdown menu to select the first day of your last menstrual period and the length of your cycle and click calculate - the calculator will do the rest!

Please select the first day of your last menstrual period:

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Usual number of days in your cycle: