Ovulation Calculator
Knowing when you ovulate is key to planning or preventing pregnancy. Since the exact day can vary each month, this calculator uses your last period date and cycle length to predict your fertile window.
Plan your pregnancy with accuracy
Enter your period date to see your fertility window
What is an Ovulation Calculator?
Knowing when you ovulate is key to planning or preventing pregnancy. Since the exact day can vary each month, this calculator uses your last period date and cycle length to predict your fertile window. Simple and science-backed, it helps you understand your cycle and improve your chances of conceiving.
Ovulation = First day of period + (Cycle length − 14)
Fertile window = Ovulation day − 5 to Ovulation day + 1