Estimated Due Date (EDD) is the expected delivery date. This calculator estimates your due date and current gestational age using Naegele's Rule based on LMP or conception date.
Only 5-10% of babies are born on their exact due date. Normal delivery can occur anytime within 2 weeks before or after. Naegele's Rule is accurate to about +/-7 days.
Naegele's Rule: Add 280 days (40 weeks) from the first day of LMP. Specifically: add 7 days to LMP date, subtract 3 months. This assumes a standard 28-day cycle.
For cycles shorter than 28 days, subtract days; for longer cycles, add days. Multiple births typically arrive earlier - the calculator adjusts accordingly.
Gestational age is counted from the first day of LMP (40 weeks total). Conception occurs around week 2. Current week shows how many weeks + days pregnant.
Key milestones: 6-8w (confirmation/ultrasound), 11-13w (NT scan), 16-20w (amniocentesis/quad screen), 20-24w (anatomy scan), 24-28w (glucose test), 36-40w (weekly visits).