My Due Date Calculator is an online tool to Calculate When Your Baby is Due. Find out when your baby is due and other important information regarding your pregnancy. Find out when your baby is due and other important information regarding your pregnancy. Calculate when your baby will be due based on your last menstrual period or conception date. So when will that baby of yours make the big debut? Unfortunately, calculating your pregnancy due date is an inexact science at best. Only five percent of pregnant women deliver on their due dates (which is why it's called an estimated due date), and any time within two weeks of that is considered perfectly normal (even if it doesn't seem like it to you!). But still, having a pregnancy due date — even an imprecise one — is better than not having one at all. If nothing else, it gives you a date to circle (in pink? or blue?) on your calendar. Pregnant? Calculate your baby's due date (and what week of pregnancy you are in) with our helpful due date calculator. Once a woman learns that she is indeed pregnant, the very next thing she would want to do is to mark out her due date. Here begins the confusion of whether she should count 9 months from the current date or from the date that conception many have happened. To simplify things, a woman needs to look at her pregnancy as a forty week period, during which various developmental changes occur in the growing fetus and at the end of which a fully formed baby will be born.