I'm not exactly sure if this is the purpose of a blog post. I might've been told before, but if that's the case, I've certainly forgotten. I've been looking around on the Wiki for a place to stick this, and I've finally landed on my blog space.
I've been curious about the population inside the walls for a while (I'll be including the Wall Titans and deceased Pure Titans too). My guess is that in total, there are probably some million Eldians on the island. I know there will be a bunch of inconsistencies, but oh well (that's inevitable, and given the amount of information we have... it's not very likely that everything's consistent).
We'll start with the Wall titans. Based off of Rikao Yanagita's calculations, there should be close to 600,000 titans in the walls -- 585,000 to be more accurate.
Now I'll calculate an approximate around of Pure Titans based off of groups and titan kills, respectively. For the amount of Pure titans that were formerly on the island, there are: the Eldia Restorationists, Ymir's Cult, and many more. I'll estimate around 100 people as an average, so that's 200 more titans on the island (which should all be dead).
Eren punched around twenty titans, so 220. For Levi Squad, they've had almost 100 total kills in solo (Levi should've killed more titans since his last stats came out). For total team kills, there are around 130 (Levi's are unknown). I'll divide this number in half (after all, it's "team kills") to get 65. I'll add on another extra 150 for the sake of other characters not mentioned. There are now 535 (Pure/non-Wall Titans) titans on Paradis Island.
Next, for the actual amount of people. The operation to reclaim Wall Maria took 250K lives, which was 1/5th of the population of "humanity". That's 1,250,000 people. I'm not sure whether or not that is supposed to include the population of the underground as well.
To sum it up: 1,250,000 + 535 + 585,000 = 1,835,535 Eldians on the island.
Well folks, there you have it. My rather inconsistently loose calculations of the population of Paradis Island. I don't know if somebody has done this before, but I do know that I've spent 45 minutes of my time in a rather interesting way. There could've been way more, there could've been way less -- ultimately, this is my take on the population of Paradis Island.
Edit: I've heard from somewhere that the surface area of Paradis is twice that of Germany's. Germany has a population of over 80 million. Paradis doesn't seem to be that dense of an island, eh? Lots of farmland, if so. Something that I find interesting is that Paradis is rich in resources... so why were they unable to support a large population? Undeveloped cities, or do the walls hinder this? Horses don't like running that far? Corrupt government too lazy, not enough MPs? Hmm. Maybe this calls for another blog post.