How many weeks pregnant am I?

Gestational age is commonly counted from the first day of the last menstrual period in weeks + days.

What are the trimesters?

Roughly: 1st weeks 1–12, 2nd weeks 13–26, 3rd week 27 to birth. Definitions can vary slightly by source.

No. Educational estimate only. Discuss dating and care with your clinician.

Calculate from

First day of LMP

Gestational age

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Educational estimate only — not medical advice. Dating is confirmed clinically. Contact a healthcare professional for pregnancy care.

Why count from LMP?

Conception timing is often unclear; LMP is a standard reference point for gestational age charts.