Estimated Fetal Weight (Hadlock) Calculator
Estimate baby’s weight from ultrasound measurements (Hadlock 3 formula).
Your result
Ultrasound weight estimates can be off by around 10–15%. Your clinician uses them with growth trends, not as a single answer.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the Estimated Fetal Weight (Hadlock) Calculator do?
Estimate baby’s weight from ultrasound measurements (Hadlock 3 formula). Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: estimated fetal weight; baby weight from ultrasound; hadlock formula.