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Pregnancy Due Date Calculator

Calculate your estimated due date based on your last menstrual period or conception date.

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Disclaimer

This calculator provides estimates for general information purposes only. Results are based on standard formulas and may not reflect your individual circumstances. Always consult a qualified professional for advice specific to your situation.

Frequently Asked Questions

How accurate is a due date calculator?
Due date calculators are accurate to within about 1-2 weeks for most pregnancies. Only about 5% of babies are born on their exact due date. The estimate is more accurate when based on a first-trimester ultrasound measurement (crown-rump length) than the LMP method, as cycle lengths vary between women.
What are the trimesters of pregnancy?
The first trimester is weeks 1-12 (organ formation, highest miscarriage risk). The second trimester is weeks 13-26 (the 20-week anatomy scan occurs here, and you typically start feeling movement). The third trimester is weeks 27-40 (rapid growth, preparation for birth). Full term is considered 37-42 weeks.

What is Pregnancy Due Date?

A pregnancy due date calculator (also called an estimated date of delivery or EDD calculator) predicts when your baby is likely to be born based on the first day of your last menstrual period or your conception date.

How this calculator works

Using the LMP method, the calculator adds 280 days (40 weeks) from the first day of your last period — this is the standard Naegele's rule used by doctors worldwide. Using the conception date method, it adds 266 days (38 weeks). The progress bar shows which trimester you're in (1st: weeks 1-12, 2nd: weeks 13-26, 3rd: weeks 27-40), and the milestone timeline marks key dates including the 12-week scan, 20-week anatomy scan, and full term at 36 weeks. Only about 5% of babies arrive on their exact due date.

All calculations are performed in your browser — your data never leaves your device. Results are for general guidance only and should not be considered professional financial advice.

Built and maintained by Konstantin Iakovlev. Data sourced from the ATO and official Australian government sources.