Hadlock Estimated Fetal Weight and Percentile

Calculate estimated fetal weight (EFW) using Hadlock formula from biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Maps EFW to gestational age-specific percentile.

Weight
Height
Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.
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How It Works

Calculate estimated fetal weight (EFW) using Hadlock formula from biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Maps EFW to gestational age-specific percentile

Each component has a specific meaning:

  • Hadlock formula from biparietal diameter — The hadlock formula from biparietal diameter recorded for the scenario being assessed.
  • Head circumference — The head circumference recorded for the scenario being assessed.
  • Abdominal circumference — The abdominal circumference recorded for the scenario being assessed.
  • Femur length — The femur length recorded for the scenario being assessed.

Note: Interpret the hadlock efw percentile result against the thresholds and context described above.

How to Use

Enter the Hadlock formula from biparietal diameter, head circumference, abdominal circumference, femur length for the scenario you are assessing. Calculate estimated fetal weight (EFW) using Hadlock formula from biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Maps EFW to gestational age-specific percentile. Use the hadlock efw percentile result to inform your calculation.

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Frequently Asked Questions