Ovulation calculator

When are you most fertile?

Using our ovulation calculator can help you pinpoint when it is best to try to get pregnant by predicting your most fertile days. Get a personalized ovulation calendar based on your cycle dates and improve your chances of conceiving!

The results are an estimation, the dates provided can be affected by cycle length and cycle regularity. We recommend that you use this ovulation calculator along with an ovulation predictor kit, observing cervical mucus or a basal body temperature chart - these tools combined will give you the best chance to indentify your fertile window.

First day of your last period


Ovulation information

You are most fertile during the few days before ovulation occurs. Ovulation usually occurs approximately 14 days before the end of your menstural cycle (the first day of your next period). Sperm can survive in a friendly environment for several days, and for this reason it is a good idea to include some baby-making intercourse well prior to ovulation. The typical fertile window is about 5 days - around 13 to 17 days before your next period is due.

If your cycle is very short (less than 21 days) or quite long (more than 35 days), or it varies by more than three days from month to month, the dates generated by this calculator may not be accurate. If you have questions or concerns about when you may be ovulating, it is best to discuss them with your healthcare provider.


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