Conception Date Calculator
Calculate your likely conception date based on your due date or last menstrual period. Estimate when fertilization occurred.
This calculator estimates when conception likely occurred based on your due date or last menstrual period. Conception typically happens during ovulation, about 14 days after the start of your last period — though the exact timing varies by individual cycle length.
Tips for Conception Date
Conception typically occurs during ovulation, roughly 14 days after the first day of your last period (for a 28-day cycle)
Sperm can survive up to 5 days in the reproductive tract, so conception could have occurred days before ovulation
An early ultrasound (6-8 weeks) provides the most accurate dating if your cycle is irregular
Frequently Asked Questions
How accurate is a conception date calculator?
Data sources: Standard mathematical formulas
For informational purposes only. Not financial, medical, or legal advice. Always consult a qualified professional for decisions affecting your finances or health.