Pregnancy Conception Calculator
Calculate the estimated date of conception based on your due date or last menstrual period.
Input Parameters
Results
Understanding Conception
Conception typically occurs around day 14 of a 28-day cycle (ovulation). Sperm can survive up to 5 days in the reproductive tract, so the fertile window spans about 5 days before ovulation through the day of ovulation. These are estimates — actual conception timing varies.
What is the Pregnancy Conception Calculator?
This calculator helps expecting mothers accurately estimate their exact date of conception based on their ultrasound due date or the first day of their last menstrual period (LMP). It is a vital tool for tracking fetal development timelines and preparing for the trimesters.
How It Works (Formula)
In a standard 28-day menstrual cycle, conception typically occurs about two weeks after the start of the last menstrual period. The calculator mathematically reverse-engineers the standard 280-day gestational timeline.
$$ \text{Conception Date} = \text{Due Date} - 266 \text{ days} $$
Estimating conception based on a standard 40-week gestation.
How to Use It
Choose whether you want to calculate based on your estimated due date (EDD) or the first day of your last period. Input the date, and the calculator will instantly provide a timeline showing your estimated conception date and trimester breakdown.