The actually calculations are easy. The general form for doing this is MgDL = MgD * (1/2)^(D/HL). MgD is milligrams in depot, MgDL is milligrams in depot left, D is days, and HL is the half-life in days. If your mathematically inclined you can also do in logs but I am lazy and this is close enough. So say you took a shot of 800mgs Testosterone Cypionate, which has a half life of 12 days, on Monday, by Sunday you would have 800*((.5)^(7/12)) or 534mg left in the depot. 800-534=266mg that you actually got that week from that shot. If you took another 800mg shot on the following Monday you would (504+800) *((.5)^(7/12)) or 870 left in the depot at the end of week two. 1304-870=434 that you actually got to use during week two and so on. As you can see the long esters take quit a bit of time to get to the weekly dosage. Please note that the calculation for week two starts out with D being 8 instead of 7, hence the 504 instead of the 534.