Aortic Valve Area Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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Cardiovascular measurements can carry a lot of meaning, so the math should stay transparent. Aortic Valve Area Calculator converts the entered values into one focused clinical estimate.

What this calculator does

Aortic valve area can be estimated with the continuity equation by comparing blood flow through the left ventricular outflow tract with flow across the aortic valve. This calculator performs that echocardiographic calculation. Cardiovascular measurements are highly context-dependent, and technique, symptoms, medications, and the rest of the clinical assessment can be as important as the calculated value.

How to use it

Enter or select LVOT, Vₜ₁, and Vₜ₂. Use the units offered by the calculator and keep measurements consistent when you plan to compare results over time.

How the calculation works

First, LVOT area = 0.7854 × LVOT diameter². Aortic valve area = LVOT area × LVOT VTI ÷ aortic-valve VTI. Enter the LVOT diameter, LVOT velocity-time integral, and aortic VTI in the units shown.

Example

For the sample values prefilled in this calculator, the primary result is 2.454 cm² (Mild stenosis range). This example is there to show how the inputs flow through the implemented equation; replace the sample values with your own measurements before using the result.

How to interpret the result

The calculated area is reported in square centimeters and grouped by the calculator’s severity ranges. The number should be interpreted with transvalvular velocity/gradient, flow state, symptoms, ventricular function, and the rest of the echocardiogram.

Limitations and notes

The LVOT diameter is squared, so small measurement errors can have a large effect on valve area. Irregular rhythm, low-flow states, poor Doppler alignment, subaortic obstruction, and inconsistent measurement locations can also distort the continuity-equation result. Echocardiographic diagnosis should use the full study, not this number alone. For clinical use, confirm that the measurements were obtained with the technique assumed by the formula. Repeating a measurement under standardized conditions can be more informative than over-interpreting a small numerical difference.