Conception Date Calculator
Conception Date Calculator
Find out the estimated date when your baby was conceived based on your Due Date.
Estimated Conception Date Range
Date – Date
Conception usually occurs exactly 38 weeks before the due date.
How is the Conception Date Calculated?
A full-term pregnancy generally lasts about 40 weeks (280 days) starting from the first day of your last menstrual period (LMP). However, conception does not happen on the day of the LMP. It typically occurs during ovulation, which is usually around 2 weeks (14 days) after the LMP.
Because of this biological timeline, your conception date is estimated to be exactly 38 weeks (266 days) prior to your Estimated Due Date (EDD). Our calculator subtracts 266 days from your due date and provides a 4-day window where conception was most likely to occur.
Frequently Asked Questions
Is this date 100% accurate?
No, this is a highly educated estimate. Because sperm can survive inside the female body for up to 5 days, and ovulation times can vary from month to month, determining the exact day of conception is scientifically difficult.