Fetal Weight Calculator

Measurement unit

Gestational weeks (optional) weeks

Biparietal diameter (BPD) Centimeter(cm)

Head circumference (HC) Centimeter(cm)

Abdominal circumference (AC) Centimeter(cm)

Femur length (FL) Centimeter(cm)

Estimated fetal weight (EFW): -

Error range: -

Reference range for GA (P10–P90): -

Growth assessment: -

GA from biometry: -

Hadlock (AC+FL): -

Hadlock (BPD+AC+FL): -

Hadlock (HC+AC+FL): -

Hadlock (BPD+HC+AC+FL): -

Shepard (BPD+AC): -

Advice: -

Fetal Weight Calculator

Estimate fetal weight (EFW) from ultrasound biometry using Hadlock and Shepard formulas. Supports cm/mm, optional gestational age with approximate P10–P90 reference, and a simple small/normal/large tip. For reference only—not a diagnosis.

Inputs

AC is most important for weight; AC+FL or BPD+AC is enough to compute.
Adding BPD/HC enables more Hadlock variants.

Notes

Typical ultrasound EFW error is about ±10–15%.
Growth trend across visits matters more than one estimate.
All calculations run locally in your browser.

Disclaimer: Consult your obstetrician for clinical decisions.