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Our online tools will provide quick answers to your calculation and conversion needs. On this page, newly pregnant moms can calculate the due date or expected date of baby's birth and the current week into pregnancy. The baby due date is just an estimate since it is difficult to determine the exact date of conception.
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Your doctor will count the start of your pregnancy from the first day of your last menstrual period. That's about two weeks ahead of when conception actually occurs.
Our calculation for expected date of delivery is based on Naegele's Rule, which is a standard way of calculating the due date for a pregnancy, assuming a 40-weeks gestational period for childbirth.
Due date formula
Baby due date = First day of last menstrual period + 1 year - 3 months + 7 days