Saturday, 10 September 2022

Estimating the size of the Mortal Realms

Age of Sigmars Mortal Realms, a bunch of spheres or whatever hanging in the void, connected by Realmgates and a bunch of other magics.

But how BIG are they? Games Workshop has been a bit cagy, but, perhaps unwisely, they have left enough information behind for me to take a veeeery rough stab at an estimate.


As a start we can use the size and available land area of our own planet as a basis;

Surface area of earth = 196.9 million mi

Estimated land area of this is roughly 30%, so = 57,268,900


Its been stated that human can walk from the centre to the edge in "a lifetime".

So, assume a walking pace of 20 miles per day.  (will likely go up in youth and down in age, this may be optimistic but at least its simple). That's 7,300 miles per year.

Lets say 70 years of walking as an optimistic average.

So that's a radius of 511,000 miles

If I jam this into an internet calculator that does equations for me I get = 8.2×10 11

Is that 8.2 billion square miles?

In raw numbers I think its =   82,033,581,529

If we assume, like earth, its 70% water we get = 24,610,074,458.7 square miles for one mortal realm.

Divide that by the earths land area = 57,268,900

We get 429.7284295437838

So best guess land area of each mortal realm is 420 TIMES the land surface of the earth?


To get the total available surface area of all mortal realms, x the raw number by eight = 656,268,652,232

But assume, like earth, that only 30% is 'land'

So estimated total land area for all the Mortal Realms is = 196,880,595,669.6 square miles.

I don't even know how to comprehend a number this big... But if we divide 196,880,595,669.6 by 57,268,900 we get=


Shorten that to 3,437

So the mortal realms land surface in TOTAL are about three and a half thousand TIMES larger than the land surface of the earth.


Due to the influence of magic and cross-realm agriculture, plus likely massive depopulation in the Age of Chaos, plus are we counting Skaven? Goblins? Plus we know the core parts of each realm are more liveable for mortals in most cases.....

But as a nice round number we can say that before Fritz Haber, about 1800 our earth had about 1 billion people.

So X that by 3,437 = 3,437 billion mortals

About 491 TIMES more people than there are on earth at this moment.


GW has been quite clever and, for most realms, not shown the full extent of the realm in any map. This means if they need more land area in the future they can just zoon out.

However with Hyish, the realm of light, they seem to have shown the whole thing in one go..

Eight large equal continents and a bit in the middle. Say the middle bit is roughly half the size of the major continents. Dividing the total by 17 might give rough size of Xintil

82,033,581,529 / 17 = 4,825,504,795.823529

Shorten that to 4,825,504,796 square miles

Hyish is clearly less hydrous than earth, but by how much, general impressions can be deceptive so I will say 50% water.

That gives me 2,412,752,397.911765 square miles

Earths land area is 57,268,900 square miles

Divide one by the other and we get 42.13023819056704

So, Xintil, the smallest central continent of Hyish in the realm of light, and the most liveable, is roughly 42 times larger than the entire land surface of the earth?

That's pretty intense.

Its so much insanely bigger than earth, even this zoomed in section of Xintil has probably several times more landmass than earth;

So lets throw up a best-guess spread of the earths area against this map;

So, even one of those very zoomed in areas, , say this little fragment of coasts and sea based around the Elidor range;

A dot on the map

Could be a giant combination empire/culture equivalent to some of the largest Empires our world has ever seen - bigger really. You could tell entire sagas set entirely within this square, based around travel and novelty, and never run out of new and very different cultures and places to visit.


What about rain? On earth very big continents often have deserts near the middle. Can rain clouds even make it that far over gigantic landmasses? Maybe the rain is coming from another dimension or something.

Travel - there would be a massive class difference between people, or magical beings who travel long distances, by flight, magic, or otherwise, or realmgates, because for most people even if they travel as much as someone travelling between every part of the British or Spanish empires at their greatest extent, they still haven't gone very far in relation to the size of the realm.

Story limitations for normal humans - its near impossible for relatively normal people to have stories where they range a long way between realm landmarks without the , whole story being the Odyssey or something. Yes there are realmgates, but they are point to point, even travelling across that red square by airship would be like circling the world probably multiple times.

On the other side there is so much room for strange forgotten or lost things, really an impossible-to-fill amount.

The awareness of near-infinity in AoS cultures really makes it a very different world to ours. There is always more.. no real limit so far as an ordinary life is concerned.


  1. Games Workshop has no sense of scale, but I suppose few authors do

  2. Is this the consequence of making a setting big enough to (in the hope of the creators) sustain multiple 'Sabbat Worlds' level series?

    Also, one conceives that AoS distance might be radically compressed by airships, magic, portals &c - Cf. Star Wars.

    1. I think a main deal is that the design team was really really tired of a relatively small world where its very hard to introduce entirely new factions.

      But yes I was also thinking they have enough space to effectively give all their authors a huge slice. Still the few AoS authors working with continued series seem to be much more focused on linking via character than via place or culture. Even in 40k relatively few people seem to want a 'section' of the Galaxy that's theirs, I think only Abnett and Fehervari stand out as doing so.

      Regarding compression of distance via magic - well the writers will get daffy and basically do that in a fudgy way anyway but if were are to take a slightly more hard-edged view; Realmgates are point to point, and not necessarily the points you were looking for, and how fast can an airship go? Even Phineas Fogg took 80 days to cross that red patch on the map.

    2. Now you've said that, I can see a 'Cross the Realm in 80 Days' story being quite fun, as a sort of civvie-AoS travelogue. Like Verne, you can throw in an over-zealous Stormcast pursuing the protagonist and his valet for a bit of obligatory drama.

      I think Sandy Mitchell carved out a few planets of his own for Cain to jaunt around. Obviously not a worldbuilder like Abnett and Fehervari, but they did seem genuinely his - if for no other reason than because half of them had convoluted puns for names.

    3. Airships could cruise at around 115 kilometers per hour (LZ-127 "Graf Zeppelin"). If you can cruise non-stop (magitech-bullshit) you can go around our world within 14 days. The actual rounding of the world with LZ-127 (the one historical event I would attempt to partake in if I ever got my hands on a time machine) took 39 days but it was more of a cruise with lots of detouring and stops in places along the way. So your red area can be crossed in a month with an airship. You could conceivably travel from one end of that realm to the other in one or two years without using gates. I guess.

    4. Always willing to nerd out on airships. I once met the great-granddaughter of an actual airship corsair who did commit an actual act of airship piracy in world war I. At a a reading of an airship book, of course.

  3. I've seen this before in Magic: The Gathering's Dominaria and toyed with it myself. I can't speak for AoS or MtG but for me there was an unfounded worry that a smaller, earth-sized world may not be able to contain all the possibilities and ideas that I thought I would come up with. It turns out my imagination ran out long before the allocation of land areas.

    1. Aye. Mundane reality is larger and more detailed than we think. Still, I do quite like the potentiality of a near-infinite frontier, even or especially if it can never be entirely realised.

  4. I think you missed a digit in paragraphs 11/12.

    511,000 x 511,000 x pi =

    So your conclusion to the size of a Realm should be 4,200 times that of Earth, not 420.

    1. 20 miles a day on average seems high though. A healthy person with modern gear & provisioned on a prepared trail does that on a good day. Factor in extended stops for rest, illness, arranging provisions, asking directions, getting lost, and most significantly moving over rough wilderness or using trails not going exactly in the right direction could make 2 miles a day (14 miles a week average) not totally unreasonable imho.

    2. Totally depends on the landscape and infrastructure. If it's open plains and you're the Mongolian Horde (tm), you'll be a lot faster than 20 miles per day. Same if you've got shippable waterways. If you're on foot but it's a roman-style road system, 20 miles per day are realistic even on the long term. If it's dense wilderness though, yes, it may be two miles. Or you just die of disease. People often vastly underestimate the danger and difficulty of travelling even distances that you can commute today.

      So yeah I'm with you, 20 Miles seems optimistic for most scenarios. Which is why most trade was done by sailing in the past. But then: AIRSHIPS!!!!111!!! (See my comment further up about average cruise speeds of Zeppelins).