Riddle me this batman, if Vegeta weighs 56 kilograms and he is ~50% muscles and Astolfo weighs 56 kilograms but isn’t ~50% muscles, where would this extra mass go? Astolfo lacks any prominently heavy feature which implies that his body is either very compact *or* the prominently heavy feature is hidden. As the fate series tries to be an anime and not a hentai we will never see truly see Astolfos penis in all it’s glory so wouldn’t that be the perfect place to hide it? To have Astolfos massive cock make up several kilograms of weight. So let’s say for simplicities and the human minds sake that Astolfo’s cock is only 20% of his body mass and that the rest was compacted into his body. This would mean that his cock weighs 11,2 kilograms. On average, 1 cubic centimeter of penis weighs in at ~0,0010703363 kilograms. This means that Astolfos absolute monster cock would have a volume of ~10 500 cubic centimeters. This equals 10 500 ml in volume. 

To put this into perspective, the average human penis is about 170 ml in volume and it’s average weight around 160 grams. Astolfo’s penis is at least 10 500 ml in volume and weighs 11 200 grams. And this is all on the low end of the calculative spectrum. “But what of the testicles?” I hear you say! Tis a discussion for another time, as I am tired from all this math. Have a pleasant day!