Normal T range seems to depend on how old you are and who you want to believe.
A guy names Lee Myer who blogs and writes books about
testosterone gives the conventional 'normal' range for testosterone as follows: A typical normal male testosterone level range given is 260 -1080 ng/dl as (which corresponds to about 8.8 - 36.7 nmol/l).
He disapproves of this range calling it "completely lame and utterly useless." He goes on to tell why he thinks that anything under 500 ng/dl may be too little, no matter how old you are. He is clearly a T enthusiast but he does give numbers and a useful units conversion, saying: On this page I am only talking about total testosterone and in all cases I use values given in ng/dl. If you want to convert to, say, nmol/l, you must use a conversion factor of 29.4 or .034 going the other direction.
For a more balanced look at testosterone you might check out this article from Men's Journal:www.mensjournal.com/magazine/the-testosterone-dilemma-20121122
It quotes some authorities with different opinions about
"normal" levels but it doesn't end up giving any numbers of its own.
Neither of these sources talk much about
testosterone in the context of prostate cancer survivors but the Men's Journal article does mention Dr. Morgentaler who has opinions about