Exactly! Read my post. Different methodologies. This is probably where the 54.7 number came from. If that 54.7 number was really comparable to labcorp numbers you would see A LOT of people with natural free T of 20+Something I don't understand here. I just pulled out my last lab results from Quest Labs. Quest states that the Reference Range for Free Testosterone is 30.0 - 135.0 pg/mL. What am I missing?