What do you mean when you say "equal"?
A common misunderstanding all over the net is that shorter esters are more potent than longer esters simply because they contain more test per mg. Obviously, short esters do contain more test per mg, but they are NOT more anabolic, per mg.
Resarch going back to at least the 50's shows that longer esters, per mg, provide a greater muscle-building effect compared to shorter esters, depsite the increased percentage of testosterone contained in the shorter esters, per mg.
There are two reasons many users believe shorter esters provide a greater myotropic effect compared to long esters, which are:
1.) A mentioned above, shorter esters provide more test per mg, so the automatic assumption is that a larger usable percentage if testosterone translates into greater growth potential. However, the effect the ester has on total protein synthesis, is almost always completely discounted.
2.) Because shorter esters are released and used more quickly, gains come faster during the first few weeks of the cycle.
In light of the above, it is easy to see how someone could easily assume that shorter esters provide a greater anabolic effect per mg. I mean, it makes sense, right? It does on the surface, but when a testosterone ester's ability to cause an increase in protein synthesis is tracked over it's entire lifetime, the longer esters will eventually catch up and exceeed the short ester. Numerous studies have been done comparing the anabolic effects of shorter esters to longer esters. This was one of the first things reseracher's wanted to know when they started attaching esters to steroids about 80 years ago (the 30's). A study was done not to long ago, showing that a 200 mg injection of test enth was able to elevate protien synthesis over 250%+, while a 200 mg injection of test prop was under 200%. I have since forgotten the exact figures, as it was over a decade ago when I first become aware of this study, but this study's findings are consistent with all the other research was has taken place over the last several decades involving esterification and its effect on protein synthesis.