A baby is considered term between 38 and 40 weeks gestation. However when we get to the magic 'due date', we feel under pressure, maybe personally or from health care professionals for a large number of reasons. Your health, baby health, baby size, your age etc. It's interesting how the due date is calculated, you may be surprised. Alexia Leachman, Founder of Fear Free Childbirth shares details below, and if you want to download her free due date calculator, click here.