Calculating FT/TT ratio

[Tommy Wall]

I can´t get around the calculation to arrive at the correct ratio
TT 583 ng/dL ref 165-788 ng/dL (QL)
FT 25.8 pg/mL ref 12-39 pg/mL (QL) I´m well within this range

But when I try to calculate the ratio converting the ng, pgs etc... its not even half % but well within the range (12-39pg/mL) .
What I´m doing wrong?

 

[Vince]

Calculating Free & Bioavailable Testosterone

 

[Tommy Wall]

Thx Vince! Anyway I think I did the calculation correct
25.8 pg/mL is 2.58 ng/dL so 2.58/583 = 0.004% which is really low since it should be 1.5+%. But the FT range is in pg/mL 12--39 for men »50 years old and mine is 25.8 which is well within the range. That´s what confusing to me. 583 x 2% for instance is 11.66 ng/dL which would be 116.6 pg/mL which is really high if the top range considering the range 12--39 pg/mL.

 

[Tommy Wall]

I don´t get in why FT ranges for men in pg/mL varies so much for instance
12--39 and other have 46--224 it is because they use different methods or?