Free Androgen Index Calculator

The Free Androgen Index (FAI) calculator helps estimate the amount of unbound testosterone in the blood, which is available to exert biological effects. This is particularly useful in assessing androgen status in women and men.

Input Parameters

Calculation Results

Calculation Formula

FAI = (Testosterone × 100) / SHBG

Where:
- Testosterone: The level of testosterone in the blood
- SHBG: Sex Hormone-Binding Globulin, a protein that binds to testosterone

Interpretation

- Low FAI: May indicate hypogonadism
- Normal FAI: Typically within the range of 5-20 ng/dL
- High FAI: May indicate hyperandrogenism

Free Androgen Index Calculator Usage Guide

Learn how to use the Free Androgen Index Calculator and its working principles

How to Use the Calculator

  1. Enter your Testosterone level in ng/dL (nanograms per deciliter).
  2. Enter your Sex Hormone-Binding Globulin (SHBG) level in mg/dL (milligrams per deciliter).
  3. Click the "Calculate" button to compute your FAI.
  4. The result will be displayed in ng/dL.

Understanding the Results

The Free Androgen Index (FAI) is a laboratory test used to estimate the amount of testosterone that is not bound to SHBG and is therefore biologically active. It helps in diagnosing conditions related to androgen levels:

  • Low FAI: May indicate low testosterone levels (hypogonadism), which can cause symptoms like fatigue, decreased libido, and muscle loss.
  • Normal FAI: Typically falls within the range of 5-20 ng/dL, suggesting normal androgen levels.
  • High FAI: May indicate high testosterone levels (hyperandrogenism), which can be associated with conditions like polycystic ovary syndrome (PCOS) in women or acne in men.

Important Notes

The FAI calculation is an estimation and should be interpreted in the context of the individual's overall clinical picture. It is recommended to consult with a healthcare professional for proper interpretation of test results and appropriate medical advice.