In a Tumblr post from March that was recently picked up by Uproxx and BuzzFeed, user marauduers4evr looked at the age-old question of just how many students attended at Hogwarts at any given time. The most commonly accepted answer comes from a 2000 J.K. Rowling interview, where she states that “There are about a thousand students at Hogwarts,” so in the 16 years since fan have started at 1,000 and worked down.
And we also know that Rowling named 40 students in Harry’s year, according to a decades-old list she has on them, who are marked by House and parentage.
According to math done by BuzzFeed, if you assume that there are around the same number of students in each year (who are then divided evenly among the Houses), that gives you about 35 students assigned to each House. That’s double the amount of students who were shown being led to Gryffindor Tower in Sorcerer’s Stone—although that likely wasn’t an actual statement on how many Gryffindors there were that year. The number of Gryffindors we meet in the books are even lower. We only see eight of them: Harry, Ron Weasley, Hermione Granger, Neville Longbottom, Seamus Finnigan, Dean Thomas, Lavender Brown, and Parvati Patil.
But the numbers didn’t quite make sense for marauders4evr, who offered a much sadder reason for the lower number of students in Harry’s year: there are fewer students because they were born during the height of Voldemort’s reign (1979-1980) and perhaps many adult witches and wizards didn’t want to bring a child into that world. And who knows, maybe Voldemort’s downfall sparked its own kind of baby boom in the ’80s.While that very well could explain the generally lower number of Harry’s year, the numbers itself is worth examining.
The size of the study body at Hogwarts has been in contention for years. A 2007 post from the Harry Potter site Beyond Hogwarts posits that the number of students is probably closer to something like 280 students instead of the 1,000 number. One post from r/harrypotter worked from the bottom up to come with about 560 students. And the idea that there was a lower number of students in Harry’s year because of Voldemort has been brought up before. (It’s also a way for some fans to explain the math discrepancy.)
But that 2000 interview isn’t the only time Rowling has spoken about the population of Hogwarts. She addressed it in a 2005 interview with MuggleNet and The Leaky Cauldron just after the release of Half-Blood Prince, noting that “about 600 sounds right” based off the 40 students in Harry’s year—although she adds the disclaimer that math wasn’t her strong suit and that “600 out of the whole of Britain is tiny.” Also, while she may have planned to have more than 40 students in Harry’s year, that number eventually stuck.
“I never consciously thought, ‘That's it, that' s all the people in [Harry’s] year,’ but that's kind of how it's worked out,” she told Melissa Anelli and Emerson Spartz. "Then I've been asked a few times how many people and because numbers are not my strong point, one part of my brain knew 40, and another part of my brain said, ‘Oh, about 600 sounds right.’ Then people started working it out and saying, ‘Where are the other kids, sleeping?’”
It’s a thought she elaborates on more in a Pottermore post about the original 40 students.
“While I imagined that there would be considerably more than forty students in each year at Hogwarts, I thought that it would be useful to know a proportion of Harry's classmates, and to have names at my fingertips when action was taking place around the school."
Will we ever truly know the number of Hogwarts students? Probably not, because actual numbers are rarely ever as clean-cut as simple division by year and House. But whatever it is, Hogwarts is magically able to hold them all and teach them just the same.