Calculating your due date

This calculator can help you estimate the date your baby will arrive. Pregnancy usually lasts 280 days (40 weeks) from the first day of the woman's last menstrual period. This calculator is a general guide: every pregnancy is unique, and sometimes babies arrive sooner or later than expected. Always talk to your health care provider about your due date.

Once you're pregnant, be sure to have regular checkups by a doctor, certified nurse-midwife or other health care professional during the course of your pregnancy. The goal of prenatal care is to monitor the progress of a pregnancy and to identify potential problems before they become serious for either the mother or the baby.

Fertilization of the egg usually takes place 14 days before the woman's next period. If your menstrual cycle is shorter or longer than 28 days, select the number of days from the start of one cycle to the start of the next cycle.