Nobody answered the question yet.
Actually we have, several times........ Perhaps you missed it?
IMO that's entirely too subjective a question, it depends on cure (water adds weight without changing the important parts), grind, packing and a bunch of other stuff. The best guide is
'it's about half the volume as 'native''? That is if you load about 1/4 gram normally (like I do), it's going to hold about 1/8. And take a bit longer to exhaust? And it will extract as well as other similar vapes.
You get out what you put in. Nothing magic. If that's enough for you, well and good. If, OTOH, it's not then you'll have to swap in another capsule and carry on. If it's plenty, you're done. If that's too much for a single session for you, you'll still be 'saving some for later', although less than native. Only sure way to determine 'if it fits your pistol' is to try it. You're the only guy who can give a meaningful answer?
FWIW I recommend them. I don't recall a single poster saying he's tried them and abandoned the idea?
Regards,
OF
Edit: Here's a good analogy I think: How many drinks are there in a bottle of Whiskey? A guy I used to work for's father in law claimed four. And lived by it. If, OTOH, you're a true Scotsman you know the real answer, it's 18.......buy coincidence the exact number of holes on a Golf Course......
Best answer is 'about half', it's slightly shorter inside than outside by the rim on the cap is fairly thin so the ID is less by a fair bit. Factor in that old 'pi R squared' thing and it's about half the volume.
Those really 'in the know' immediately notice the flaw in that: 'no, no, no......pie are
round, cornbread are square'......
OF