Ovulation Calculator

The ovulation calendar predicts the approximate dates when you may ovulate and be fertile, and is intended for use by those with regular menstrual cycles.

Member? login and your menstrual tracking history will fill in the last period and average cycle length fields below! (See: Help for details)

Step 1. Ovulation Calculation Rule

Your ovulation cycles will be calculated using the data specified below.


Step 2. Ovulation Calendar Display

Calendar Date Book

Other ways to determine and understand your fertility cycles: charting your fertility cycles; And, using ovulation/fertility prediction tests. Talk to your healthcare provider or medical doctor about which methods are best for you.

Important: The information on this ovulation calendar should not and cannot be used to prevent pregnancy.

Disclaimer: The information on this ovulation calendar should not and cannot be used to reliably prevent pregnancy. This ovulation calculator is not intended for those having irregular menstrual cycles; if your cycle is irregular, talk to your healthcare provider regarding methods that can help determine your fertility cycles. Even if your cycles are regular, we make no guarantee that your period, ovulation, and/or fertile days will occur on the predicted dates shown on the calculated ovulation calendar, since each person's menstrual and fertility cycles can vary in any given month for a variety of reasons.

All information provided on this ovulation calculator, including predicted dates of menstruation, ovulation and fertile days, is for educational purposes only. It is not intended as a substitute for advice provided by a medical doctor or qualified healthcare provider. You should not use this information for self-diagnosis or for treating a health problem or disease. If you have any questions whatsoever about your medical health or believe you have a medical problem or disease, you should contact your medical doctor or healthcare provider.