How accurate is conception date calculation?

Conception date calculations are estimates with a margin of error of several days. Sperm can survive up to 5 days, and ovulation timing can vary, making exact conception dating challenging.

Conception Calculator – Conception Date Estimator

Calculate conception date from due date or birth date. Estimate when conception occurred for pregnancy planning.

Conception Calculator – Conception Date Estimator

Calculate conception date from due date or birth date. Estimate when conception occurred for pregnancy planning.

Calculate From*

Calculate conception from due date or birth date

Reference Date*

Due date or birth date

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Enter reference date to estimate conception

Understanding Conception Dating

Conception typically occurs about 266 days (38 weeks) before birth or date-calculator" class="text-primary hover:text-primary/80 underline underline-offset-2 transition-colors">due date. This calculator estimates the conception date, though the actual conception could have occurred within a few days of this date.