Estimated Fetal Weight (EFW) Calculator
Health & FitnessEstimate fetal weight from ultrasound measurements using the Hadlock formula.
Estimated Fetal Weight
Estimated fetal weight using the Hadlock formula, based on abdominal circumference, head circumference, biparietal diameter, and femur length.
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Odeh Ahwal0people find this calculator helpful
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Frequently Asked Questions
What is the Hadlock formula?
The Hadlock formula is a widely-used method for estimating fetal weight from four ultrasound measurements: abdominal circumference, head circumference, biparietal diameter, and femur length.
How accurate is estimated fetal weight?
Ultrasound-based fetal weight estimates typically have a margin of error of about 10 to 15 percent, so treat the result as a useful estimate rather than an exact weight.
Does this calculator tell me my growth percentile?
No. This calculator gives you the estimated weight itself. Comparing that weight against a percentile chart for your exact gestational age requires the growth chart used by your doctor, since the reference data needed for a precise percentile is not built into this tool.
Why are four different measurements needed?
Using multiple body measurements together, rather than just one, produces a more reliable weight estimate since it accounts for natural variation in body proportions.
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