Gestational Age & Due Date Calculator
Calculate official estimated due date (EDD) and gestational age based on SOGC determination guidelines.
Average Menstrual Cycle Length28 days
SOGC Dating Guideline Rule
If first-trimester ultrasound CRL dating disagrees with menstrual dating by > 5 days (at < 9 weeks) or > 7 days (at 9–13+6 weeks), the ultrasound date overrides the LMP to determine the official clinical EDD.
Calculation Summary
Enter your dates on the left to calculate EDD and gestational age.