EDD & GA calculator

The EDD & GA calculator estimates a due date from a last menstrual period, conception date or a known due date, finds gestational age at any date, and converts birth weight between grams and pounds/ounces.

Open it from the Patients group in the sidebar. The same tool is public at /tools/edd-calculator, so you can share it without a sign-in.

Due date & gestational age

Under Calculate from, pick your starting point:

Last menstrual period (LMP)
Date of conception (DOC)
Known due date (EDD)

Enter that date in Selected date, and optionally a date in Gestational age on to see the gestational age on a specific day. The results appear as Estimated due date and Gestational age.

The dating uses LMP + 280 days or conception + 266 days; gestational age is measured from the LMP, and dating from conception adds 14 days to stay on the same baseline.

Date at a gestational age

The second card works the other way: choose a basis (LMP, DOC or EDD), enter the date, and enter a number of weeks and days to find the calendar date the pregnancy reaches that gestational age.

Birth-weight converter

The third card converts a birth weight between pounds and ounces and grams in either direction — enter one side and read the other.