Doing the Math: How many kids are at Hogwarts?

On October 16, 2000, J.K. Rowling gave a live interview on Scholastic.com with classrooms across America, which were allowed to ask her questions about the books up until then (at the time, Goblet of Fire), one of the earliest of these kinds of interviews with J.K.
When a student asked, “How many students attend Hogwarts, and how many students per year per house?” she replied, simply, “There are about a thousand students at Hogwarts.”
And because she said it, this has persisted as the proper answer accepted by most fans. But I don’t see how that could be correct.
So, let’s do the math. There are four houses at Hogwarts, so if there are 1000 students, that means each house has 250 students in it (1000 divided by 4). There are 7 years at Hogwarts. So, if there are 250 students in each house, that means there are approximately 36 students in each year in each house (250 divided by 7 equals 35.7).
That means, if we assume there are approximately the same number of boys and girls in each year, that there are approximately 18 boys in Harry’s year. But besides Harry, throughout all seven books, we’ve only ever seen four others (Ron, Neville, Seamus and Dean).
Another thing, we don’t see a lot of actual classes at Hogwarts, but we see some in the course of Harry’s adventures, and others are mentioned. On page 135 of Harry Potter and the Sorcerer’s Stone (page 100 of Philosopher’s Stone), Harry asks what class they have next, and Ron replies, “Double potions”. We can’t tell for sure from the books, but I’ve always assumed that “double potions” meant two houses together, as well as a double class time period. In any event, we can be sure from the books that a double class means the students of two houses together.
But that means, if we use the counts from above, that there would be about 72 kids in double potions class. That sounds like way more kids than would fit or could be handled in one classroom, even by Snape.
And, we’ve seen McGonagall call all her students into the Gryffindor common room for important announcements. I can see 70 kids stuffed into that room, but 250?
I know the movies are not cannon, but they also disagree with the above numbers.

This is an image from Sorcerer’s Stone, from the sorting feast, the second before food appears on the table, and on some of the rows you can quite clearly count the number of empty plates on the tables (click on the image above to see the full-size image). As you can see, in the rows that can be completely counted, there are 33 plates on each side of the table, which would make 66 students per table. Even if that shot is not of the complete dining hall floor, it is certainly most of it, and even if there are few plates in the foreground that we cannot see, it still places the number of students per table in the 66-70 range.
I believe there are, indeed, 70 students at each table. Here is how I calculate the Hogwarts math:
We know that there are, including Harry, five Gryffindor boys in Harry’s year at Hogwarts. Assuming that there are the same number of girls as boys, that means there are 10 students in Harry’s year in Gryffindor at Hogwarts. Since there are 7 years, that means there are 70 Gryffindor students total at Hogwarts, and since there are 4 houses, that means there are only 280 students all together at Hogwarts. Quite a different number than J.K.’s thousand.
The number of students in our double potions class now makes a lot more sense, 10 Gyrffindors and 10 Slytherins makes 20 students, a very normal student class size, especially for a “lab” kind of course.
Another scene in the movie kind of agrees with my Hogwarts math.

This is the scene where the first years are following Percy up the stairs to Gryffindor Tower for the first time. If you look closely, not counting Percy who is right-most in the picture, there are 13 students. A few more than the 10 in my math, but a lot closer to my number than the 36 in J.K.’s count.
Do you think this count of 280 makes sense, or do you think there is evidence in the books that, as J.K. said, there are more students at Hogwarts?
And, if there are only 280 students at Hogwarts, how does that speak to the general population count of Wizards to Muggles? If there are only 280 kids in Hogwarts, how many wizarding families could there be in Britain? Or is it possible there are other wizarding schools besides Hogwarts?

12 thoughts on “Doing the Math: How many kids are at Hogwarts?”

  1. ive always thought there were a very small amount at hogwarts and i think around 200-300 would be a reasonable guess, i dont think there would be 1000, but in GoF, jk writes, describing the amount of witches and wizards at the quidditch world cup ‘a hundred thousand witches and wizards’, so if there are that many witches and wizards from around the world, i think it could be possible that there are a lot of people at hogwarts. also, at my school when we have 2 periods of the same subject together, we call it a ‘double period’ so i always assumed that ‘double potions’ was two periods. i also always thought that ALL classes had two houses in it, cause they always say ‘potions with the slytherins’ or ‘herbology with the hufflepuffs’.

  2. Well, perhaps this is just me trying to defend J.K’s statements, but perhaps there is less people in Gryffindor as not so many are brave and all that other kind of stuff, i expect that hufflepuff would have the most students, as helga hufflepuffs house takes students no matter what, while Gryffindor, Ravenclaw and Slytherin have certain qualities they are looking for… I dont think it would be safe to assume that the students are divided evenly, which i think we experiance in one of the books but i cant remember.

  3. Great article again. I think 280 count is well calculated, there are 280~ students in Hogwarts. I think there are a lot of wizarding schools in the Rowling’s world. Lets say half of the Wizards marry with Muggles, and other half marry with each other. A family has 2 kids overall so 280/7 = 40 students per year. 40/2= 20 families needed for one year. Families are made by 2 people, so we need 30 wizards and 10 muggles for a year. Lets say, a wizard have a baby when he/she is overall 27 years old (fair isn’t it?), so we need 27 years to make other births. 27×30 is 810 wizards. Do we have 810 wizards in the world? I don’t think so. I could say, 1 school is enough for England in this numbers don’t you agree? How many English/England-related wizards are in HP World?

  4. I think the counts reflect well of the movie. But, movies often times condense content so as not to overwhelm the viewer with something that goes just fine in a book. It would be interesting to see Dave’s numbers projected out against the population of England compared with JKR’s numbers. How many families and wizards/witches are there really in the country? The world? Is the Statute of Secrecy protecting a small portion of the population, or a large one? If it is too small, it would just fade away; too large, and there would be no need for the SoS!

  5. I totally agree with the article. I’ve been thinking about his for a while too, and I ended up with around 300 students. Ten in every year for every house, what would be 10 x 7 x 4, and that’s… 280, and to make it a round number 300, ’cause it’s possible that a few more or less, it would be pretty odd if every year exactly 40 new students arrived at Hogwarts. Besides, if there were 250 students in every house, the common rooms have to be huge. And about the ‘double potions’ thing: I think means two hours and not two houses together, because in my opinion, every class there are two houses together (of the same year). That would be 10 x 2 = 20 students, that’s quite a normal number. I’m quite sure I’ve read it somewhere in the books, or at least something that would assume it…

  6. I’m sure the article is much more likely than JKR’s estimate, but really, she probably never thought of it until the student asked her, so a thousand would be the best number she thought of at the top of her head. I’m sure that a first year, when writing home, would guess the same amount. The grandeur of the place and the new faces would suggest as much.

  7. I too, am sceptical of this analysis. If Rowling said about 1000, this should be right, she planned it out didn’t she? I do admit you’d end up with huge class groups, but seeing that Hogwarts is not a Muggle High School, should we really compare? Couldn’t we just as easily compare with University, where classes are thaught to hunderds of students at the same time? Okay, there’s only eight Gryffindors in Harry’s year that we know of (Harry, Ron, Seamus, Dean, Neville, Hermione, Lavender and Parvati) but maybe it just wasn’t a great year for Gryffindors. And true, we don’t see that many characters intoduced in the books, but look at you own situation at school. Do you know everybody that stu s there? I don’t think you do, do you? There’s a group of friends, a group of foes and an awfull bunch of familiar but unidentified faces. Should you really base part of your plea on the number of identified students there are? I admit having 1000 Hogwarts Students would complicate a lot, but having only a mere 300… It seems so little to me. I rather think Rowling inteded for at least 1000 students to be at Hogwarts, because wizarding community would be too small otherwise, but never really figured out (or bothered to) how to show that huge amount in the books. I really don’t think she cared about the mathematics or maximum student numbers in classes. Harry’s birth-year could just as easily have a very low birth rate, so there’s little students in his year, and that’s why they pair houses up for classes. And really, I don’t think every house gets roughly the same number of students… (And probably, I just don’t want to budge, because I’ve been fighting similars pleas for years now, I can’t help but persist in defending my opinion)

  8. I think JK’s count is pretty accurate because she wrote the book and planned it out didn’t she? so if she really did do that, then she probably counted the way you first did. Without looking at the scenes from the movies, you can determine the number. Since they probably couldn’t get 1,000 kids and adults in the movie to act as a whole wizard population, they modified it to about 10 or 14 (as you mentioned) students per scene. If you think about it in your mind, there is probably about 400 students in one middle/elementary school in a suburb. That means that if there is 1 house per school, and (we’ll substitute grades for houses) there are 4 grades at the school, then 400 divided by 4 houses give you 100 students per house. then if you take that and divide by 7 for every year, you get 14.285714. if you round that to about 14 to 15 students per year, then that doesn’t make sense. if we do it JK’s way, it makes more sense. 1000 is a much more reasonable number to be working with and thinking about while calculating student body population. and plus, there could be millions of wizard families in the HP world. I could be living next to one right now…

  9. Well I think that J.K. is right but only from the counting of the BOOKS.The movies are completely different then the books. They couldnt have that many people for a movie so they settle with a smaller number of people. Also there are different wizarding schools. For example Durmstrang and Beuxbatons. There must be more schools than that also because in HP and the GoF when Harry is at the Quidditch World Cup Harry says he sees kids about his age he didnt know. Then he realizes there are kids from different schools because Hogwarts couldn’t be the only one.

  10. We must remember that there are not even numbers of students in every house. Taking Harry’s year for example, we see there are 5 boys and 3 girls in Gryffindor, however in Slytherin, there is a smaller number of students in their year. There are only 4 boys and 2 girls, noted. So, it is impossible to estimate how many students there are, since we don’t know the exact number of any given year. Also, maybe 1000 she meant it had the capacity to hold 1000, not the actual present student body. As an additional note about the number of wizarding families. We are told in ly Hallows that it is not mandatory to send your child to Hogwarts. There are those who go abroad and those who are home-schooled, just like in the Muggle world of schools.

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