Enter the aortic diameter and patient height into the calculator to determine the Aortic Height Index (AHI). You can also use the tabs to calculate Aortic Size Index (ASI) or Body Surface Area (BSA), and solve for any missing variable when the other two are known.
Important: For educational use only; not medical advice. Do not use this tool to diagnose disease, predict personal risk, or make treatment/medication decisions (including drug dosing). Aortic measurements should come from an imaging report and be interpreted by a qualified clinician. If you have sudden severe chest/back pain, fainting, shortness of breath, or stroke-like symptoms, seek emergency care.
Aortic Height Index Formula
The following formula is used to calculate the Aortic Height Index (AHI).
AHI = Aortic Diameter(cm) / Patient height (m)
What is an Aortic Height Index?
The Aortic Height Index (AHI) is a measurement used in medical imaging to relate aortic size to a patient’s height. It is typically calculated by dividing an aortic diameter measurement (commonly the maximum measured diameter of a specified aortic segment, in cm) by the patient’s height (in m). Indexing aortic diameter to body size may be used as one factor alongside absolute diameter, growth rate, symptoms, family history, imaging technique/segment, and condition-specific guidance (for example, connective tissue disorders or bicuspid aortic valve).
What this calculator cannot do
This calculator cannot diagnose an aneurysm, determine whether the aorta is “normal” for you, or decide if/when surgery or other treatment is needed. For clinical decisions, follow clinician interpretation and established guideline recommendations (for example, ACC/AHA guidance) based on your specific aortic segment and medical history.
How to Calculate Aortic Height Index?
The following steps outline how to calculate the Aortic Height Index (AHI).
- First, determine the aortic diameter (cm).
- Next, determine the patient height (m).
- Next, gather the formula from above = AHI = Aortic Diameter (cm) / Patient height (m).
- Finally, calculate the Aortic Height Index (AHI).
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem:
Use the following variables as an example problem to test your knowledge.
Aortic Diameter (cm) = 4
Patient height (m) = 1.8
AHI = 4 / 1.8 = 2.2222 cm/m
