Free online ovulation calculator: track your fertile window, ovulation day, and next period. Based on your cycle length for family planning and fertility awareness. Mac OS 9 retro style.
Select the first day of your last menstrual period using the date picker. This is the starting point for all calculations.
Enter the average length of your menstrual cycle in days. The average cycle is 28 days, but cycles can range from 21 to 45 days.
Enter how many days your period typically lasts, usually between 3 and 7 days.
Click Calculate to see your ovulation day, fertile window (the 6-day window when conception is most likely), and your next expected period.
Q: How accurate is this calculator?
A: This calculator provides an estimate based on average cycle lengths. Individual results may vary. For personalized advice, consult your healthcare provider.
Q: Can I use it with irregular cycles?
A: This calculator works best with regular cycles. If your cycle length varies significantly, the results may be less accurate.
Q: Does a fertile window guarantee pregnancy?
A: No, a fertile window indicates the days when conception is most likely, but does not guarantee pregnancy. Many factors affect fertility.