How far do the grounds of Hogwarts extend through the Forbidden Forest

Question

"Of course," said Moody, taking a swig from his flask. "Took a leaf out of your book, Potter. Summoned it from my office into the forest. He wasn't anywhere on there."

"So he did Disapparate?" said Ron.

"You can't Disapparate on the grounds, Ron!" said Hermione.

I'm using this as proof that the Forbidden Forest, or at least the far eastern (see this question) side of it, is part of the Hogwarts ground. Anyway, my question is where was the boundary of the Hogwarts grounds? I have no idea how big the forest is, but it doesn't really matter; how much of it was part of the Hogwarts grounds? The whole forest, or just part? How much?

Answer 1

This is JK Rowling's hand-drawn Hogwarts map. As you can see, a great deal of the Forest appears to be part of the grounds. With the heavy outline that seems to be the boundary where it is, it could be fairly safely inferred that the whole thing is, but it is certainly a pretty fair amount.

I don't know if you'll get more specifics than this at this time.