A sense of scale

[Adrian Laguna]

That certainly puts things into a new perspective.

There is no other way of reading it. The Imperium of Man controls about a million "world", which I suppose could include moons and planetoids. A paltry average population of a million persons per world gives a total population of a long billion. I'd peg the actual average at at least 10 million, given that hive worlds tend to have populations in the tens of milliards, and its apparent that they have a few thousand of the things.

[Elessar]

Actually, I think the WH40K franchise does a pretty good job with scale.

For the most part, I agree, but I think even GW itself doesn't get the entire scale of its setting. The part in the main rulebook about the Imperial Guard consisting of countless" billions" when you'd need more along the line of countless trillions to cover what else is depicted in the setting.

While the numbers might not be completely accurate, the imagery often shown (visuals or through literature) does suggest scale quite well. Pretty much every Imperial Guard landing I've read suggested that to the inhabitants of a world, it looks like the sky is falling. Enough ships to darken the sky descending constantly onto a world, for days upon end.

And of course, that's usually just a small fraction of the force nearby.

For the most part, they do pretty well ensuring the reader is aware of the vastness of its setting. Most of the time, the reader doesn't even need to crunch numbers. And that's important, since most people don't really have a feel for large numbers. The Powers of Ten video still surprises mainstream audiences, and that's been around since the 70s.