Fetal Weight Percentile Calculator
Calculate estimated fetal weight percentile using ultrasound measurements and WHO growth standards
Calculate Fetal Weight Percentile
Basic Information
Valid range: 14-40 weeks
Ultrasound Measurements
Measured at liver level
Around thalami level
Distance between parietal bones
Length of thigh bone
Fetal Weight Assessment Results
Enter all ultrasound measurements and gestational age to calculate fetal weight percentile
Valid gestational age range: 14-40 weeks
Example Calculation
20-Week Fetus Example
Gestational Age: 20 weeks
Gender: Unknown
Abdominal Circumference: 154 mm (15.4 cm)
Head Circumference: 180 mm (18.0 cm)
Biparietal Diameter: 56.2 mm (5.62 cm)
Femur Length: 30 mm (3.0 cm)
Calculation Result
Estimated Fetal Weight: ~334g
Percentile: 50th percentile
Category: Normal Range
Interpretation: Average weight for gestational age
Percentile Categories
Key Information
Based on WHO multinational growth standards
Uses Hadlock formula for weight estimation
Valid for 14-40 weeks gestational age
Requires all four ultrasound measurements
Results are estimates - consult healthcare provider
Medical Disclaimer: This calculator provides estimates for educational purposes only. Always consult with qualified healthcare professionals for medical advice and clinical interpretation of ultrasound findings.
Understanding Fetal Weight Percentiles
What are Fetal Weight Percentiles?
Fetal weight percentiles compare your baby's estimated weight to other babies at the same gestational age. A percentile indicates what percentage of babies weigh less than your baby at that specific week of pregnancy.
Clinical Significance
- •SGA (<10th percentile): May indicate intrauterine growth restriction
- •Normal (10-90th percentile): Expected growth for gestational age
- •LGA (>90th percentile): May indicate macrosomia or diabetes
Ultrasound Measurements
Abdominal Circumference (AC)
Measured at the level of the liver and stomach
Head Circumference (HC)
Measured around the widest part of the head
Biparietal Diameter (BPD)
Distance between the sides of the head
Femur Length (FL)
Length of the thigh bone
Hadlock Formula
Where EFW is Estimated Fetal Weight in grams, and all measurements are in centimeters. This formula is widely used in obstetric practice for fetal weight estimation.