The estimated due date (EDD) is the date that spontaneous onset of labor is expected to occur.

Due dates serve an important clinical purpose as they provide information on when to intervene, speed things along, and get that baby out.

**Formula to calculate pregnancy due date**.

- First, identify the first day of your last menstrual cycle.
- Next, add 9 months and 7 days to it.

**Example:**

If the first day of your last menstrual cycle was 27th November, determine your due date.

When we add 9 months to November 27th, we get September 27th.

Then add 7 days to September 27th, we get 4th November.