Amniotic Fluid Index (AFI) Calculator
Amniotic Fluid Index (AFI) Calculator adds the deepest vertical fluid pocket measured in each of the four quadrants of the uterus to estimate how much amniotic fluid surrounds the baby. The formula used is: AFI = Q1 + Q2 + Q3 + Q4. Enter each quadrant depth in centimetres.
Rates and fees change frequently. Always confirm the current figures
with the official authority before relying on this result.
- For information only — interpretation requires your sonographer or obstetrician.
Formula
AFI = Q1 + Q2 + Q3 + Q4 (deepest vertical pocket in each of the four quadrants)
- Amniotic Fluid Index (AFI) Calculator gives you a fast estimate using your inputs and updates instantly when you change any value.
- Formula: AFI = Q1 + Q2 + Q3 + Q4 (deepest vertical pocket in each of the four quadrants)
- Input definitions: • Quadrant 1 (right upper): the numeric quadrant 1 (right upper) used in the calculation • Quadrant 2 (left upper): the numeric quadrant 2 (left upper) used in the calculation • Quadrant 3 (right lower): the numeric quadrant 3 (right lower) used in the calculation • Quadrant 4 (left lower): the numeric quadrant 4 (left lower) used in the calculation
- Manual method: write down each input, apply the formula step by step, then compare your manual result with the calculator output.
- Enter values using the units shown next to each input field (e.g. kg, cm, years).
- This calculator uses widely accepted health formulas and returns screening estimates only. It does not replace a diagnosis from a qualified healthcare professional.
- Compare your result with published reference ranges. Values outside the normal range warrant a conversation with your doctor.
- Practical tip: test a low, medium, and high scenario to understand sensitivity before making decisions.
Example Calculation
Inputs
- Quadrant 1 (right upper): 4 cm
- Quadrant 2 (left upper): 4 cm
- Quadrant 3 (right lower): 3 cm
- Quadrant 4 (left lower): 3 cm
Suppose you enter: Quadrant 1 (right upper) = 4, Quadrant 2 (left upper) = 4, Quadrant 3 (right lower) = 3, Quadrant 4 (left lower) = 3. The calculator applies the formula (AFI = Q1 + Q2 + Q3 + Q4 (deepest vertical pocket in each of the four quadrants)) and shows all output values below. Change any input field to immediately see how the result changes.
Frequently asked questions
What is the Amniotic Fluid Index?
The AFI is the sum of the deepest vertical amniotic fluid pocket in each of the four quadrants of the uterus, measured by ultrasound. It estimates whether fluid volume is low, normal, or high.
What is a normal AFI?
A typical normal range is about 8–18 cm, with 5–25 cm often considered acceptable. Below 5 cm suggests oligohydramnios and above 24–25 cm suggests polyhydramnios.
What units should I enter?
Enter each of the four quadrant measurements in centimetres, as reported on the ultrasound.
How accurate are the results?
The sum is exact, but interpretation depends on gestational age and measurement technique. This is a screening estimate, not a diagnosis.
How do I interpret the result?
Compare the total with the normal range shown. A value outside it warrants discussion with your sonographer or obstetrician.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.
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