Due date calculation 2.0

The usual way of calculating your due date is the `Naegele method`. It simply adds 280 days to your last period, or 266 days to your last ovulation date.



The `Mittendorf-Williams method`, shown on this page, takes more factors into account, like race, coffee consumption and education. Some studies have found this to be more accurate than the usual way in calculating due date.



Note: Use this method during the first trimester, and trust your doctor rather than an online calculation

1st day of last period