Calculator · Women's / obstetric

Gestational age (from EDD)

Current gestation and trimester from a known estimated due date (e.g. the dating-scan EDD).

What it is for

Quick "how many weeks?" from the scan EDD — for scan timing and reading medicine-safety information.

Use the working calculator

The working Gestational age (from EDD) calculator is on our calculators page. It is free and needs no account. Enter the values and it shows the result with the reading that goes with it.

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What you enter

The calculator asks for one item.

  • Estimated due date (EDD) (a date)From dating scan or LMP.

How the result is read

The result is shown as Result. Formula: GA today = 280 − (EDD − today), in weeks+days.

The calculator reports one of these readings, with the action that goes with it: EDD already passed by; Term —.

Sources

These are the sources the calculator cites. Check the current version before relying on a threshold.

Related

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For qualified clinicians. A score supports a clinical decision and does not make it: check the inputs, read the cited source, and use the tools in your clinical system for patient care where one is provided.