Yea, not really making a habit out of it, but I had to clean her enclosure anyway, so I didn't really need to do anything special to weigh her. I've tried this http://serpwidgets.com/main/measure a couple times and I get anywhere in the 7' range. I think that's accurate because her skin is 9'.
I have a measure app on my phone, but by the time I get it all set, he's on the move.
I'm guessing he's anywhere between 8 and 10 feet.
I'd say you are probably in the ballpark with your guess.