Our calculator can help you track your ovulation to determine the days in your menstrual cycle which give you the highest chance of conceiving–commonly known as your ‘fertile window’.
When you know your fertile window, you and your partner can time when you have sex to increase your chances of getting pregnant.
How to calculate your fertile window
1. Enter the first day of your last menstrual period.
2. Enter the average length of your menstrual cycle. This is the number of days between the first day of bleeding of one period, and the first day of bleeding of your next period. This tends to vary from 23 to 35 days. If you have irregular menstrual cycles, it may be difficult to calculate your ovulation date.
3. See the dates that you are most likely to be fertile. The ‘fertile window’ is the days leading up to and including ovulation. You are most fertile 2 to 3 days before you ovulate. You and your partner can use these dates as a guide to time when you have sex, and increase your chances of getting pregnant.