DueDateCalculator.ai

Pregnancy timing

Pregnancy Week Calculator

See exactly how far along you are — your gestational age in weeks and days, your trimester, and your due date.

Your details

The first day bleeding started.

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

Pregnancy is counted in gestational weeks from the first day of your last period — so “how far along” is the number of completed weeks and days since then.

Nearly all prenatal milestones and appointments are scheduled by this number.

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

The formula
gestational age = today − last perioddue date = LMP + 280 days

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. 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. Gestational Age CalculatorGestational age for any date you choose.