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Amniotic Fluid Index Calculator

Work out amniotic fluid index instantly with clear inputs, formula shown and shareable results.

About Amniotic Fluid Index Calculator

Adds the deepest vertical fluid pocket from each of the four uterine quadrants to give the amniotic fluid index.

Formula

Amniotic fluid index

AFI = sum of the deepest vertical pocket in each of four quadrants; oligohydramnios under 5 cm, normal 8-24 cm, polyhydramnios over 24 cm

Worked example

With the default values below, Amniotic Fluid Index Calculator returns Amniotic fluid index of 15.5. Change any input above and every figure here is recalculated in your browser.

Inputs used

Right upper quadrant depthaccepts 0–20 cm
4.5 cm
Right lower quadrant depthaccepts 0–20 cm
3.8 cm
Left upper quadrant depthaccepts 0–20 cm
4 cm
Left lower quadrant depthaccepts 0–20 cm
3.2 cm

Results

Amniotic fluid index
15.5 cm
Category
Normal (8 to 24 cm)
Deepest single pocket
4.5 cm
Mean quadrant depth
3.88 cm

Step by step

  1. 1Values used
  2. 2Amniotic fluid index
  3. 3Amniotic fluid index= 15.5 cm
  4. 4Category= Normal (8 to 24 cm)
  5. 5Deepest single pocket= 4.5 cm
  6. 6Mean quadrant depth= 3.88 cm

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Is single deepest pocket better?

Yes for diagnosing oligohydramnios: using AFI leads to more interventions without improving outcomes, so many units prefer the single pocket measure.

What single pocket depth is abnormal?

Under 2 cm defines oligohydramnios and over 8 cm suggests polyhydramnios.

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