8" Traditional Granny Square

Okay... my 6" blocks from the book 200 Crochet Blocks have all been turning out to be 8" instead. I'm using a 4mm/G hook and #4 weight yarn (rather than sport weight yarn--#3).

I thought all of my blocks would be 6" and I was at 6" at the round right before the last one so I stopped (if that makes sense?). When I realized my blocks were going to be 8" instead, I just added the last round to it, and it turned out exactly 8".

Here's a picture:

I love this block!