This calculator provides an estimate only based on Naegele's Rule (LMP + 280 days). Only about 5% of babies are born on their exact due date.
This tool is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider for accurate pregnancy dating.
Naegele's Rule: The due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).
Conception Date Method: If you know the conception date, the calculator subtracts 14 days to estimate the equivalent LMP, then applies Naegele's Rule.
Trimesters: First trimester spans weeks 1-13, second trimester weeks 14-27, and third trimester weeks 28-40.