Free Testosterone Index (FTI) Calculator for Healthy Adult Male
Typical values for a healthy adult male undergoing routine hormone evaluation.
Estimates the Free Testosterone Index (FTI) using total testosterone and SHBG levels. Enter your Total Testosterone, SHBG – Sex Hormone-Binding Globulin to get an instant free testosterone index (fti). Formula: (total_testosterone / shbg) * 100.
Free Testosterone Index (FTI)
Fill in the fields above and click Calculate
Comparison ()
| Field | |
|---|---|
| Result |
Formula
Step-by-step
Variables
Recent Calculations
How It Works
How It Works
The Free Testosterone Index (FTI) estimates how much of your total testosterone is available in relation to sex hormone-binding globulin (SHBG). SHBG is a protein that binds to testosterone in the blood, reducing the amount that is freely available to the body.
The calculator divides your Total Testosterone value by your SHBG value and then multiplies the result by 100. This creates a percentage that reflects the balance between testosterone and SHBG.
- Enter Total Testosterone in nmol/L
- Enter SHBG in nmol/L
- The formula used is (Total Testosterone / SHBG) × 100
- The result is shown as a percentage (%)
- Higher ratios generally suggest more available testosterone
Understanding the Results
The Free Testosterone Index (FTI) gives a simple percentage that helps estimate how much testosterone may be available for your body to use. It does not directly measure free testosterone, but it provides a useful approximation.
A higher FTI may indicate relatively more available testosterone, while a lower FTI may suggest that a larger portion of testosterone is bound to SHBG.
- The result is expressed as a percentage (%)
- Higher values may indicate greater testosterone availability
- Lower values may suggest more testosterone is bound to SHBG
- Results should be interpreted alongside lab reference ranges
- Always discuss results with a healthcare professional
Disclaimer
This health calculator is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Disclaimer.