How to calculate your due date (LMP, ultrasound, and IVF)

Use these tools while you read—keep the same LMP or ultrasound anchor your clinician documented.

Pregnancy due date calculator · Due date by last period · Pregnancy week calculator · How many weeks pregnant · FAQ hub · How to calculate due date (blog)

LMP method: start at the first day of the last menstrual period and add 280 days in the classic teaching frame—our calculator automates the calendar math.

Ultrasound method: assign gestational age at the scan, then extrapolate to an implied 40-week line—useful when cycles are irregular.

IVF method: follow documented transfer day and embryo age conventions from your fertility clinic paperwork.

If you manage a chronic condition, bring your medication list to every visit—even if the topic page is about something unrelated like trimester milestones. Drug safety questions belong in a charted conversation, not a comment thread.

Nutrition pages should never shame food culture. If guidance here conflicts with your clinician’s advice for gestational diabetes, hypertension, or hyperemesis, follow the personalized plan—those conditions override generic tips.

This article is educational. It does not diagnose, treat, or triage emergencies. Always follow your licensed obstetric clinician, midwife, or local emergency guidance.