View Full Version : Imperial Guard Tithing

02-05-2009, 14:24
I've been wondering a lot recently about how many soldiers could be raised from a planet each year, and I'd like to share my results.

I'll start with current day earth.

Planetary fertility is around 20 per 1000 of population each year, or 134 million new Imperial citizens each year.

As the life expectancy is about 70 years, that equates to about 1400 children per 1000 over a lifetime, 2.8 children per couple.
The replacement rate, due to accident/disease/permanent singletons is about 2.3 children per couple, or 1150 per 1000 of population.

250 children per 1400 every year could then be sent off-world before breeding without worrying about a declining population. That's a recruitment rate of 17.9%.

Earth could therefore supply 24 million soldiers each year to the imperial guard without its population dwindling. That's roughly 10,000 regiments per year.

Now Imagine something a hypothetical hive world. You maybe 20 Hives on the planet, each one containing up to 100 Billion people. That's 2 Trillion people.
The Democratic Republic of Congo manages to breed 7 children per couple, so there's no reason our hypothetical planet can't either. Public Health is good, so there's a replacement rate of 2.075 (as in the UK), so 1040 children are needed for replacement. You birth 3500 children, so 2460 can become soldiers, a 70% recruitment rate.
Globally there would be 100 Billion births a year, and so 70billion new soldiers of the Imperium from one planet each year, 30 million regiments.

I doubt it gets quite to quite that extreme an example, but it really gives a sense of the scale of the Imperial War Machine.

02-05-2009, 14:38
The biggest Hive Worlds have around 300-500 billion people, so it's not that bad.
Still, once again the mind-numbingly large numbers used by GW prove to be too small.

02-05-2009, 14:50
My source on the hive worlds was using the highest end figures from 40kwiki, so I'll be the first to admit they may be wrong.

Still, an earth-type planet with a population of 500 Billion could still produce 1.8 billion soldiers a year.

02-05-2009, 18:10
I think the limiting factor has always been transportation, getting the IG units to where they are needed - if you can't, recruiting soldiers that you can't use is a waste of resources.