what is a good size down there for a 13-15 year old ?

There really is no average.

But if there were, I would say for a 13 year old, anything 3-4 inches or less is short, 4-5 is average, and 6 or more inches is larger. For a fifteen year old, I would say 4 inches or less is short, but I would give a 13 year old a break, because male puberty usually ends around age 19.

Good luck!

Hope this helped.

Ten points please. :)

Around 5 inches is on average. At 13-15 even 4 inches is good enough.

Don't worry, love is more important than anything else.

Elaborate. Male or female? Either way it doesn't matter. There is no set size. Everyone is different a genes, the individual, race and so many thing influence these things.

are you pubescent or prepubescent

whats your race

how large are your fathers genitals :0