One of the first things most newly expecting parents want to know is when the baby’s due. Of course, the standard answer is 40 weeks, but like with most pregnancy-related things, nothing’s standard. For example, when you find out you’re pregnant, you might already be five weeks along. This represents a 12.5% swing and could be the difference between a Labour Day and Thanksgiving baby.

By factoring in your particular ovulation cycle and the first day of your last period, this due date calculator can give you an estimation of when you should expect to have your baby. Of course, your baby might have something to say about that, but only time will tell.