Medical calculator
Hadlock 4 Estimated Fetal Weight Calculator
Estimates fetal weight from BPD, HC, AC, and FL using the Hadlock 4 ultrasound formula.
Enter BPD, HC, AC, and FL from the same ultrasound examination. The primary result is estimated fetal weight in grams, with kg, oz, and lb shown as additional outputs.
Ultrasound biometry
Enter biometric measurements from the same scan. The formula uses centimeters internally.
Biparietal diameter (BPD)
Distance across the fetal head, entered in cm or mm.
Head circumference (HC)
Fetal head circumference, entered in cm or mm.
Abdominal circumference (AC)
Fetal abdominal circumference, entered in cm or mm.
Femur length (FL)
Fetal femur length, entered in cm or mm.