I quote: "A different list of half-lives is often copy and pasted on various sites, claiming that, for example, the half-life for the propionate ester is 4.5 days and that the half-life for the enanthate ester is 10.5 days. This list is incorrect, and is the result of flawed calculations by Bill Roberts many years ago. See the "References" section for more information."
"Turns out, this list is completely wrong, and was apparently based on some flawed calculation of carbon atoms by Bill Roberts many years ago. Not only is it wrong, it's really wrong - in some cases, half-lives are off by over 150%."
Study: Behre HM, Nieschlag E. 1998 Comparative pharmacokinetics of testosterone esters. In: Nieschlag E, Behre HM, eds. Testosterone: Action, Deficiency, Substitution, ed 2. Berlin: Springer-Verlag; 329–348.
You can see clearly on the graph from the study, the serum testosterone concentration spanned in hours. They actually drew blood and measured what T levels were, not just calculated...