Hello. I have a hard time understanding the ranges of free and bioavaible testosterone. I’ve read that the normal ranges are:
Total 231-1010 ng/dl (8-35 nmol/l)
Bioavaible 83-257 ng/dL
Free 5-21 ng/dl
My SHBG is 54 nmol/l and total testosterone 27 nmol/l (778 ng/dl). According to this chart: Free & Bioavailable Testosterone calculator
my bioavaible testosterone is 302 ng/dl and free 12.9 ng/dl.
(Even more confusing, according to this chart Free Testosterone Calculator
my bioavaible testosterone is 299.9 ng/dl and free 12.8 ng/dl)
According to the range my bioavaible testosterone is higher than normal. I find that very hard to believe since my SHBG is way higher than normal for my age and my total testosterone is not too high.
If we convert my values with FAI (free androgen index), the ratio is calculated like this: total testosterone (nmol/l) divided by SHBG (nmol/l) and multiplying by 100. My FAI is 50. The normal FAI ranges are 30-150, below 50 is considered low for my age. Which put my in the low end.