Longevity Fertility Centre
Ovulation Calculator
Enter the first day of your last period and your usual cycle length to estimate your fertile window and ovulation date.
Your estimated dates
Fertile window and ovulation
This is the six-day period ending on your estimated ovulation day.
Ovulation is estimated to occur about 14 days before your next period.
Your actual cycle may vary from month to month.
Next three estimated cycles
Important:
This calculator provides estimates only. It should not be used to prevent pregnancy or replace medical advice.
Ovulation may vary, especially with irregular cycles, PCOS, breastfeeding, perimenopause, illness, stress, or fertility treatment.