Ovulation Calculator

Please select the first day of your last menstrual period:
Please select the number of days in your menstrual cycle:
Conception generally occurs near the time of ovulation, but the number of fertile days before or after a woman ovulates varies. You are most likely to become pregnant if sexual activity occurs during, just before, or just after ovulation. To calculate the days when you are most likely to become pregnant, enter the first day of your last period into the calculator. To determine the number of days in your cycle, count the days beginning with the first day of your last menstrual period (first day of bleeding) up to and including the day before your next period. This calculation is only possible if your menstrual cycles are regular and is most reliable when the time between each menstrual period is in the range of 26 to 30 days.
EBSCO Information Services's proprietary interactive calculators provide general results based on input provided by the user that is calculated against measurements or formulas considered standard by various government agencies, including the USDA, CDC, and FDA. The inputted information consists only of single values (e.g., anthropometric data or activity levels) not detailed clinical information, and the results do not indicate or suggest a specific course of action unique to the user.