Pregnancy Due Date Calculator

Pregnancy Due Date Calculator A pregnancy due date calculator can be used to estimate the expected due date of a baby based on the first day of the mother's last menstrual period (LMP) . The calculation is based on the average length of a menstrual cycle, which is assumed to be 28 days, and the fertilization date, which is approximately two weeks after the LMP. The due date calculated by a Pregnancy Due Date Calculator  is only an estimate and not a guarantee of when the baby will be born. It is common for babies to be born a few weeks before or after the due date. Is the Due Date 36 or 40 Weeks? A pregnancy due date is typically calculated as 40 weeks from the first day of the last menstrual period (LMP). This means that the due date marks the end of the 40th week of pregnancy, which is considered full-term. However, only about 4% of women deliver exactly on their due date. Most babies are born between 37 and 42 weeks of pregnancy. A pregnancy is considered full-term between 37 an