Ovulation Calculator
Free Online Ovulation Predictor
Enter your last menstrual period date and cycle length to automatically calculate your ovulation date, fertile window, and next period date. Calendar view for easy visualization. Free, no registration, works entirely in your browser.
days (typically 25-35)
Ovulation Date
Fertile Window
Next Period Date
Calendar
Menstrual Period
Fertile Window
Ovulation Date
Note: This tool provides estimates based on the Ogino method. Actual ovulation dates may vary due to stress and health changes. For accurate determination, use basal body temperature tracking, ovulation test kits, or medical examinations. Do not use for contraception purposes.