By entering the first day of your last menstrual cycle this calculator can determine when your baby's due date should be.

The average gestation period for a baby is 280 days or 40 weeks measured from the first day of the mother's last menstrual period.

The 40 weeks are split into three distinct trimesters.

Fun fact. Only around 5% of babies are born on their due date because many are born early and others just don't follow your doctor's plans.