Health
Ovulation & Fertility Window Calculator
Estimate your most fertile days and expected ovulation date to maximize chances of conception.
Ovulation & Fertility Window Calculator
Estimate your most fertile days and expected ovulation date to maximize chances of conception.
This calculator provides an estimate based on averages. Do not use this as a method of birth control.
How This is Calculated
Ovulation is estimated to occur ~14 days before the next period (cycle length − 14 days). The fertile window spans approximately 5 days before ovulation through 1 day after, reflecting sperm viability (up to 5 days) and egg viability (~24 hours). This is the calendar-based rhythm method.
Disclaimer: This tool provides estimates for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
