Yeah, Fiona's right. Technically any amount of calories is a binge if it really freaks you out and you have to purge. Mine are usually about 3000 calories, though. Anyway, don't even get started throwing up/using laxs/etc. because it will just add one more complication to your life.
Plus, I personally think that it's even worse for your body than anorexia, as long as your arn't extremely skinny. Lately my chest hurts some, like in the spot of my heart, so that's kind of freaked me out some and I've layed off the binging/purging.
I don't ever do it more than once a day (hardly) and I've heard of some folks who do it up to 30 times a day. It takes over your life more than anorexia even does. It's easier to recover from anorexia in my opinion too (as someone who's had both). Just take it one day at a time and you will get through this!