Fetal Weight Calculator

Calculate fetal weight metrics, pregnancy timelines, and obstetric parameters with ease.

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Pregnancy & Cycle Inputs

Enter last menstrual period (LMP) date or cycle length.

Cycle Length (Days)

Days Since Last Period

6 Weeks 3 Days First Trimester Timeline

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Naegele's rule calculates due date by adding 1 year, subtracting 3 months, and adding 7 days to the first day of your last period.

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EDD = LMP + 280 Days (40 Weeks)

Applies American College of Obstetricians and Gynecologists (ACOG) standard guidelines.

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Calculated due dates are estimates. Crown-rump length (CRL) ultrasound scans provide definitive dating.

Follow these simple steps for pregnancy tracking:

Select the calendar date when your last normal menstrual cycle began.

Enter your average cycle length in days (default is 28 days).

Instantly view calculated due date, current gestational age in weeks/days, and trimester breakdown.

Tracking gestational weeks allows proper timing for prenatal screenings, glucose tolerance tests, and ultrasounds.

Input

First day of last period and average cycle length.

Output

Estimated birth date and current weeks of pregnancy.

How accurate is a pregnancy due date calculator?

Only about 4% of babies are born on their exact due date. Delivering within 2 weeks before or after your due date is completely normal.

When does the second trimester begin?

The second trimester officially begins at week 14 of pregnancy (covering weeks 14 through 27).