An online due date calculator. Enter the last menstrual period or the conception date to estimate the due date, current gestational age and days remaining, with reference notes for each stage. Useful for tracking pregnancy and preconception planning.
Naegele's rule: due date = first day of LMP + 280 days
Pregnancy Reference
First trimester (weeks 1–12): the main organs begin to form; take folic acid and avoid alcohol, smoking and intense exercise.
Second trimester (weeks 13–27): the baby grows quickly; screening tests such as the Down syndrome test and anomaly scan are done; keep a balanced diet.
Third trimester (weeks 28–40): the baby matures; monitor fetal movements and prepare for delivery.