DueDateCalculator.ai

Pregnancy timing

Gestational Age Calculator

Find the gestational age for any date — enter the last period and the date you want to check.

Your details

The first day bleeding started.

Defaults to today if left blank.

Days from one period to the next. Default 28.

Calculated on your device. Your dates are never sent or stored.

Enter your details to see your estimate. Every result is an estimate — your clinician sets the official due date.

How it works

Gestational age is the time since the gestational start date (the first day of the last period), expressed in completed weeks and days. Choose any date to see the age on that day.

See the full methodology and pregnancy term definitions on the main page.

The formula
gestational age = chosen date − gestational start1st ≤ 13w6d · 2nd 14–27w6d · 3rd 28w+

More calculators

Due Date CalculatorEstimate your due date from your last period, conception, or IVF transfer. Conception Date CalculatorEstimate the day you likely conceived and your fertile window. Pregnancy Week CalculatorSee how far along you are in weeks and days. IVF Due Date CalculatorDue date from your embryo transfer date and embryo age. Reverse Due Date CalculatorWork back from a due date to your last period and conception.