Pregnancy Conception Calculator
Estimate your conception date range, ovulation day, and fertile window from your last menstrual period or estimated due date.
Inputs
Results
Medical disclaimer: This calculator is for educational purposes only and is not medical advice. Always consult a qualified healthcare professional.
About the Pregnancy Conception Calculator
Conception generally happens 11–21 days after the start of your last menstrual period for a typical 28-day cycle, with ovulation around day 14. The fertile window covers the 5 days leading up to ovulation plus ovulation day itself, because sperm can survive several days in the reproductive tract.
You can also work backwards from a known or estimated due date — subtract 280 days to recover the equivalent LMP, then project conception and the fertile window from there.
Frequently asked questions
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