Due Date Calculator | natoras.com

Q: Is it normal to go past my due date?

Yes, very common. About 80% of births occur between 37 and 42 weeks. Your healthcare provider will monitor you closely after 40 weeks and discuss options if labour has not started by 41-42 weeks.

How Is a Due Date Calculated?

The estimated due date (EDD) is calculated using Naegele’s Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a standard 28-day cycle with ovulation on day 14. For longer or shorter cycles, the due date is adjusted accordingly. Only about 5% of babies are born on their exact due date — most arrive within two weeks either side.

Pregnancy Trimesters

Pregnancy is divided into three trimesters. The first trimester (weeks 1–12) is when the foetus develops its major organs and most miscarriages occur. The second trimester (weeks 13–26) is often the most comfortable, with the anatomy scan typically occurring around week 20. The third trimester (weeks 27–40) involves rapid foetal growth and preparation for birth.

When Is a Baby Considered Full Term?

A baby is considered full term at 37–42 weeks. Births before 37 weeks are premature; births after 42 weeks are post-term. Most healthcare providers will recommend induction by 41–42 weeks if labour has not started naturally.

Frequently Asked Questions

How accurate is the LMP due date method?

The LMP method assumes a regular 28-day cycle, which many women do not have. An ultrasound scan in the first trimester (8–12 weeks) provides a more accurate due date by measuring foetal size.

What if I don’t know my LMP date?

If your LMP is unknown or irregular, an early ultrasound (dating scan) is the most reliable way to estimate gestational age and due date.

Is it normal to go past my due date?

Yes — very common. About 80% of births occur between 37 and 42 weeks. Your healthcare provider will monitor you closely after 40 weeks and discuss options if labour hasn’t started by 41–42 weeks.

Medical Disclaimer: This calculator is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for health decisions.