Calculator

Due-date calculator

See an estimated due date and key milestones from the last menstrual period using a Naegele-style count.

Expectant parent planning a calendar for an estimated due date

An estimated due date (EDD) for most singleton pregnancies is often counted by adding about 280 days to the first day of the last period. This page focuses on the due date and also lists a few commonly discussed milestones.

Calculate

Result

Enter the details and press Calculate. The result will appear here.

How to use it

  1. Enter the first day of your last menstrual bleed.
  2. The tool produces an estimated due date using 280 days (40 weeks).
  3. It also lists informative milestones around weeks 12 and 20.

Points to watch

  • This date is not a “must-birth day”; babies often arrive before or after the EDD.
  • Multiple pregnancy, IVF or special medical situations may be dated differently.
  • Plan appointments and scans with your health professional.

Frequently asked questions

What is Naegele’s rule?

A commonly used practical approach: about 40 weeks / 280 days from the first day of the last period. Actual birth timing is still individual.

Can my due date change?

Your clinician may update the estimated due date from ultrasound and clinical findings. This tool does not update automatically.

Must I give birth on the due date?

No. The EDD is a guide date; labour varies from person to person.

Source and method note

Estimating a due date over about 40 weeks is a frame used in common clinical practice. This tool does not create a diagnosis or birth plan.

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