Ever wonder how there could only be about 18 Gryffindors in Harry’s Hogwarts class and that J.K. Rowling has said there were 1,000 students at the school? Well, a fan theory has an answer… a depressing, depressing answer.

Buzzfeed did the math and, assuming that all the houses have roughly equal numbers of students, there would need to be an average of 35 students per house per year for there to be 1,000 students total. (1000/7 (the number of years at the school) = 143 143/4 (the number of houses) ≈ 35).

However, the movies appear to show only 18 kids in Harry’s Gryffindor year. And it doesn’t look like there’s an explosion in the other houses to make up for that.