[Baron Spikey]

Everyone who has the vaguest understanding of 40k Background knows that there are ~1,000 Chapters, each with ~1,000 Marines which totals roughly 1 Million Adeptus Astartes (don't argue it averages out at about that).

But does anyone have any idea on the numbers of the other Imperial elite military organisations, like the Adepta Sororitas (Sisters of Battle), Storm Troopers- including Storm Trooper equivalent like Kasrkin- and Titan/Skitarii Legions?

At a guess I'd say the Sisters of Battle have higher numbers than the Astartes if only due to how they're deployed where ever there's a large enough Ministorum presence, but how many I'm not sure on as Sororitas background isn't my strong point (admitting to fluff ignorance, shocking I know).

 

[Tel Asra Nejoar]

with sisters it really is hard to say. a large number are placed at sites important to the ministorum(almost every shrine has at least a handfull according to the dex), the orders hospitaller provide the medicorps for the imperial guard(also according to the codex), then the vast majority of orders are buerocratic(sp?) in nature, being the orders famulus. so whilst there are potentially billions of siters, only a small percentage can be approximated as full on martial. if i remember the largest likely orginization of sister for a battle is roughly 1000(the same as a full chapter), though it can be assumed that many more can be organised as they are tasked with prosecuting holy crusades and are deployed to eradicate space marine chapters who show too much deviancy(early fluff, though its never been repealed). but as the candidates come from the schola progenium, we can extrapolate that around the same or fewer are recruited into the sisterhood than stormtroopers(this part is pure guesswork, but seems to be a reasonable presumption based on the idea of a narrower candidate bracket).

 

[shaantitus]

I don't know weather this is much help but in the Eye of Terror campaign book there is a list of the forces on both sides(approximate of course) The rough ratio was 170 space marine companies to 15-16 adepta sororitas Preceptories. So i would assume that the marines outnumber the sisters. Also listed were 486 companies of Kasrkin and 38 companies of inquisitorial stormtroopers.
These ratios might give an indication of the approximate relative strengths imperium wide. Hope it helps baron.

 

[Azezel]

Each of the six Orders Majoris of the Sororitas have a membership of five to ten thousand, excepting the Order of Our Martyred Lady which is supposed to be closer to twenty than to ten thousand.

There are any number of Orders Minoris - their memberships vary but somewhere between 500 and 5'000, tending toward the lower end of the scale.

The Orders Militant of the Adepta Sororitas certainly outnumber Astartes - probably by an order of magnitude. The Orders Hospitalier, Dialogous, Famulous etc vary. It seems safe to assume that the Hospitalier outnumber the Militant, and that the Dialogous and Famulous are both more numerous than Astartes, but not nearly so nuerous as the Militant or Hospitalier.

My belief is that there are around a billion Sisters of the Orders Militant, anywhere up to twice as many Hospitalier, and a million or so each Dialogous and Famulous. (But then, I've never truelly bought the idea that one million marines would even be noticable in so vast an uncaring a universe as 40k... Movie Marines or not).

It seems likely that 75%-90% of all female Progenia join one branch or other of the Sororitas. I base this purely on the stated fact that most Stormtroopers, Guard officers and Commisars are men - the women have to go somewhere...