Ovulation Calculator
Calculate your ovulation date, fertile window, and next period based on your cycle length.
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Important Disclaimer
This calculator provides estimates for educational purposes only. Results are not a substitute for professional medical or nutritional advice. Always consult a qualified healthcare provider before making significant changes to your diet or exercise routine.
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Frequently Asked Questions About Ovulation
How do I calculate my ovulation date?+
Ovulation usually happens about 14 days before your next period starts. With a 28-day cycle that is around day 14; with a 32-day cycle it is around day 18. Enter the first day of your last period and your average cycle length above to estimate your ovulation day and fertile window.
What is the fertile window?+
The fertile window is the roughly six days ending on ovulation day — the five days before ovulation plus the day itself — because sperm can survive up to five days and the egg lives for about 12–24 hours. These are the days with the highest chance of conception.
How accurate is an ovulation calculator?+
Calendar calculators are most accurate for people with regular cycles. Ovulation can shift due to stress, illness or irregular cycles. For more precision, combine the calculator with ovulation test kits, cervical mucus changes or basal body temperature tracking.
Can I get pregnant outside the fertile window?+
It is unlikely but possible, especially if your cycle is irregular and ovulation happens earlier or later than predicted. An ovulation calculator should not be used as a method of contraception.