Planning pregnancy? Wondering when you're most fertile? Use the Ovulation Calculator to help determine what days of the month you are likely to be ovulating.

To start, please fill out the information below:

1. When was the first day of your last menstrual period?


2. On average, how long is your menstrual cycle? Your menstrual cycle is the number of days between the first day of bleeding of one period to the first day of bleeding of your next period, not including that day - for most women this is approximately 28 days.


This tool provides an approximation of your fertile period and works best if the length of your periods and the time between periods is consistent. If your periods are unpredictable, the tool may not be as accurate and you should talk to your doctor.

This tool is meant for informational purposes only and should not replace the advice of your healthcare professional.