Home
Back
Gestational Age Formula:
| From: | To: |
The Crown Rump Length Calculator estimates gestational age from the measurement of the embryo or fetus from the top of its head (crown) to the bottom of its buttocks (rump). This measurement is typically obtained via ultrasound during the first trimester of pregnancy.
The calculator uses the formula:
Where:
Explanation: The formula calculates gestational age based on the square root of the crown rump length measurement, providing an accurate estimation of fetal age during early pregnancy.
Details: Accurate gestational age determination is crucial for proper prenatal care, establishing expected due dates, monitoring fetal development, and identifying potential growth abnormalities.
Tips: Enter the crown rump length measurement in centimeters. The value must be a positive number greater than zero for accurate calculation.
Q1: When is CRL measurement most accurate?
A: CRL measurement is most accurate for dating pregnancies between 7-13 weeks gestation.
Q2: How is CRL measured?
A: CRL is measured via ultrasound by identifying the longest straight line from the top of the head to the bottom of the torso.
Q3: What is the typical range of CRL measurements?
A: CRL typically ranges from a few millimeters in early pregnancy to about 8-9 cm by the end of the first trimester.
Q4: Are there limitations to this calculation?
A: Accuracy decreases after the first trimester as fetal curvature increases. Other measurements become more reliable for dating pregnancies beyond 13-14 weeks.
Q5: How does this compare to other gestational age formulas?
A: This formula is specifically designed for CRL measurements and provides more accurate results for first-trimester dating than formulas based on other parameters.