How accurate is the OSAP estimator on the OSAP site? I entered the wrong amount for my guesstimated summer income (I thought it was asking for something else), but when I went to fix it, the estimated assessment turned out to be the same. I'm not sure whether I should believe it now.

It's generally pretty accurate. This year I was estimated $800 and I actually recieved $853

I'd say it's generally accurate within $100.

Mine this year was accurate to within about 400$. (It estimated 1000$ and my total ended up being 1352$). So it's not too far off.

When I submitted the application, the actual OSAP estimate was about $1500 less than what the aid estimator said it would be. :(