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Math, My Old Nemesis



Or, how I spent an afternoon frantically trying to figure out the age demographics of the wizarding world during the 1990s. Please keep in mind that I am not great at math, but this is (loosely) based on the demographics of the UK.

That being said, if there are any grievous math errors, please let me know. And thank you to everyone in the Discord chat who brought this up so I started thinking about this.

How Many Students Are There at Hogwarts?

Okay, so it always seemed a little wonky to me how both large and small the wizarding world seemed. An example of this is how many students there are (roughly) in canon (about 240). Rowling said that there are about a thousand students in Hogwarts at any given time, but this doesn't quite match up with what we see in canon with Harry's year only having about ten Gryffindors.

But what if Hogwarts usually had about a thousand students? Or, rather, what if not every single magical child went to Hogwarts? Hogwarts does seem to be a bit smaller than the other European wizarding schools that we see in canon, unless Durmstrang and Beauxbatons brought their entire schools to the Triwizard Tournament. It could be one of the smaller schools, so anywhere in that range of numbers would make sense, given what year.

Going Down the Wikipedia Rabbit Hole

Seeing as trying to extrapolate the population of the wizarding world from the number of students at Hogwarts always went awry for me (oh, math, my enemy), let's look at the demographics of the UK. All information is from the Demography of the United Kingdom Wikipedia page here (m because it’s Wikipedia).

While I was figuring out the numbers of each demographic, I did do a little changing because the wizarding world had a war roughly ten years before we’re looking at. So what does this mean for the population?

Assuming (we are making a lot of assumptions in here, sorry) that most of the people who died in the First Wizarding War were between the ages of 20 to 40, this means that those portions of the population would be a bit lower percentage-wise. The population would be a bit higher in the younger (0-19) and older (70+) than they usually would be.

Also, fair warning, I messed up slightly in rounding, so I know that the population, technically, adds up to 55,615, not 55,617, but I messed up with the rounding and it has been twenty minutes of me trying to fix it. Just pretend those two, like, were Voldemort or something.

These also include Squibs because they are definitely part of the wizarding world and figuring out how to separate them from the magical people population is way too complicated.

A Breakdown by Age

Ages 0 to 9: 18.8 percent, or 10,456 people

This is a bit larger than it usually would be, but, since we’re talking percentages, they make up a larger portion of the population than they would if there were more people in other age groups. Also, there was probably a baby boom right after 1981, and these kiddies would be in the perfect age group to be the effects of that.

Ages 10 to 19: 12.1 percent, or 6,729 people

This would be Harry’s age, and it is a bit bigger than Hogwarts would be able to accommodate. Don’t worry. This will be addressed later in this blog entry. This, also, is a bit inflated compared to what it would have been prior to the First Wizarding War.

Ages 20 to 29: 5.8 percent, or 3,225 people

The first age group that is much lower than it usually would be. In the UK demographics, this age group makes up 13.6 percent of the population, but I have a feeling that they would have been hit especially hard by the First Wizarding War.

Ages 30 to 39: 5.5 percent, or 3,058 people

This is the age group where the Marauders and such would be in. I felt like this group would be the one hit worst by the First Wizarding War, as most of the people we see in canon who die during it were most likely born within this group.

Ages 40 to 49: 11.6 percent, or 6,452 people

Where the population starts springing back up again. They were safely out of Hogwarts by the time the First Wizarding War was fully in swing, and most of them are the parents of the children of the post-First Wizarding War baby boom.

Ages 50 to 59: 12.4 percent, or 6,897 people

Very similar to the above age group. Both of these groups were slightly smaller than usual, though only by about two percent each, but part of that is due to the younger groups and that, since wizards live much longer, there had to be an additional age group.

Ages 60 to 69: 11.4 percent, or 6,340 people

This is about a percent higher than the UK demographics. Magical people do seem to slow in their aging, and they tend to either die very young or very old, at least, in canon.

Ages 70 to 79: 9.4 percent, or 5,228 people

This is about three percent higher than the UK demographics. We see a lot of older magical people, so it isn’t surprising that there is a higher percentage of them.

Ages 80 to 89: 7.1 percent, or 3,949 people

The UK demographics have this at about 3.9 percent, but, due to the much lower percentage of younger people, this is a bit inflated.

Ages 90 to 99: 4.9 percent, 2,725 people

So, the UK demographics have the last age group be 90+, and it’s only .8 percent of the overall population. This one and the one below are so high due to the lower ages being a bit lower than they usually would be.

Ages 100+: 1 percent, or 556 people

Given what we’ve seen of older people in the wizarding world, I imagine that there are less than a thousand people over the age of one-hundred. Dumbledore was somewhere in the range of 115-150, but, if my math is right (and if there’s one thing I’ve proven in this, it’s that I am very bad at math), he was about 115 when he died, according to the ages given on the HP wiki.

Total People: 55,617 people

But Robin, you might ask, why are there so many people in the wizarding world?

Because I wanted it to be an actually viable amount of people so that purebloods and such would actually be able to do their whole ‘no contact with the Muggle world’ thing. It’s roughly the population of a densely-populated county/town, so I figured that there would be enough people for the society to actually spread out. That being said, I am not a sociologist or demographics expert by any means, and this is just a way I’m trying to make sense of holes in the worldbuilding.

Where Do the Other Children Go to School?

There are over six-thousand children from the ages of 10 to 19 that are unaccounted for due to Hogwarts’ relatively small size. So where do they go to school?

Some probably go to Beauxbatons or Durmstrang. A few probably are homeschooled. I’ve always felt like there should be more than just Hogwarts in Britain, but maybe there are a bunch of smaller schools that aren’t mentioned.

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Guest Noelle Zingarella


Robin, you're amazing.

And I just gotta say, as a parent, ain't no way I would have sent my kids to Hogwarts--least not while Dumbledore was in charge. Love that dude, but he's a tick too cavalier with student safety for my taste...

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Posted (edited)

I LOVE THIS. 😍 The research and time that must’ve gone into this! I am just gonna accept this as the official canon now, please and thank you. 😋🥰

Edited by just.a.willow.tree
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Ah, a person after my own heart. This is my second favorite topic (2nd only due designing Hogwarts class schedules--I know. I know NERD.)

My question is how did you extrapolate to a total population of approximately 55,000? Using 1,000 as Hogwarts age, I extrapolated the total wizarding population to be approximately 11,800 (however, I assume it to be even more since their life expectancy far exceeds ours.)


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4 minutes ago, potionspartner said:

My question is how did you extrapolate to a total population of approximately 55,000? Using 1,000 as Hogwarts age, I extrapolated the total wizarding population to be approximately 11,800 (however, I assume it to be even more since their life expectancy far exceeds ours.)

Answer: I messed up the cross-multiplying after forgetting that children under the age of eleven exist.

...I am not good at math.

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You've inspired me to write a blog about Hogwarts scheduling. (When time permits. . . )

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