Obstetric Dating
EDD & Gestational Age
Calculate current gestation from LMP, ultrasound, or EDD on the sonar report.
Dating method
Defaults to today. Change this to calculate gestation on a ward round or clinic date.
Use the estimated due date printed on the ultrasound report to calculate current gestational age.
Current gestational age
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Enter dates above to calculate gestational age
Clinical note
EDD is calculated using the standard 280-day (40-week) rule from LMP. Ultrasound dating in the first trimester is most accurate. Always correlate with clinical findings and local protocols.