Looking at my child's elementary school on Trulia - I can see what you mean about the class size not being accurate to actual classroom numbers. I noticed that there was a line that stated that the class average was based on the average number students per teacher at the school. So for our neighborhood school, the site is counting the 39 teachers available at the school for the 600+ students equaling 18 students per teacherâ€¦but those numbers must include support teachers (reading specialist, art, music, P.E., speech, etc) and not just the classroom teachers! It also looks like the information is about a year old too. I know our enrollment numbers are down compared to last year since a new charter school opened in our area. Most websites like Trulia pull there information from the school district websites directlyâ€¦so if the school district website is not up to date their reporting, then other websites won't be either.