Fetal Weight Calculator
Estimate your baby's weight during pregnancy by gestational week.
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Calculation Results
Estimated Fetal Weight: Week 20
0 lbs, 11 oz
Metrics Analysis
How This Calculator Works
Applies Hadlock regression averages to gestational ages, illustrating median fetal weight development.
Fetal Weight Calculator — Week-by-Week Weight Chart
Discover your baby's estimated weight and developmental length milestones during prenatal stages.
How Doctors Estimate Fetal Sizing
Obstetricians use 4 key measurements on ultrasound: Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC), and Femur Length (FL).
Growth Percentile Tracking
Fetal weights are placed on standardized curves. Falling below the 10th percentile or above the 90th percentile suggests monitoring for IUGR or macrosomia.
Clinical Standard Reference Guideline:
Hadlock FP, et al. Estimation of fetal weight with ultrasound.
Frequently Asked Questions (FAQ)
Q:How accurate is fetal weight estimation?
Ultrasound estimations have a margin of error of +/- 10% to 15%. They are math models, not physical scales.