With all of this snow, I’ve been drinking lots of cocoa. I like the kind with the mini-marshmallows in and I hate it when they’re gone before the cocoa is. Then it hit me: I could use Zuul to fill my cup! How many marshmallows could I get out of old Sta-Puft? It’s been a while since I’ve seen the movie and I can’t remember how tall he was, or how big around. What would his dimensions be? I was never taught how to calculate the volume of a vengeful Sumerian Demigod.
What say ye, Dopers?
Well, according to wikipedia, the model shop supervisor said on a DVD interview that he was 112.5 feet tall.
Nitpick: Gozer.
Zuul was the Gatekeeper.
Oops. It* has* been a while. Guess I’m gonna have to watch it again.
For science!
Okay, with the help of Google calculator to do metric conversions, and xkcd for some rough info on the volume of human-shaped figures, I estimate that if Stay-Puft were of ordinary human build, he’d be made up of approx 500 kiloliters of marshmallow. Guess-timating that a mini marshmallow is about 2 milliliters, that means you could make 250 million mini marshmallows out of human-build Stay-Puft.
I’d bump that up to something like 400 million for the Stay-Puft man in the movie, since he’s so fat and puffy. 
I found a 3D model of that guy on Google’s warehouse. Removed his hat and collar-piece-thing, shrunk him down to ~112.5 feet, and calculated his volume. See this picture:
https://www.dropbox.com/s/tjf0tiypqyvc0gy/Screenshot%202014-02-19%2020.07.27.png
Because his geometry his complex, the measurement isn’t totally accurate. But next to him is a rectangular prism of similar size, and he’s about half that volume… seems within the realm of plausibility. So if that seems reasonable, the program said he’s about 4.5 million liters.
Hmm… well, then we’re differing by about a factor of ten, which doesn’t seem huge for different ways of calculating the ‘body shape’ component.
How wide and deep are the prism, if it’s also 112.5 feet high? To get the volume you indicate, I figure it needs to be half that in the other dimensions, or around 57 feet. That’s much puffier than any human being to comparable scale would be. 
I love this thread.
You gotta factor in density, too, don’t you? Ol’ boy had to be pretty dense, given that he was able to destroy a church (and piss off Venkman) just by stepping on it.
Density and weight are irrelevant to the problem as specified, or to either Reply’s way of solving it or of mine.
Even with the low density of typical marshmallows, I think the weight would be sufficient to make a church roof cave in. If he’d stepped onto strong exterior walls maybe it wouldn’t have been enough to collapse them immediately. If the density was too high, then it wouldn’t be much good in hot chocolate.
And then there’s the whole square-root law quagmire, of whether his legs would even be able to support his weight. But hey, an ancient evil god did it!
Figuring 10 mini-marshmallows per 10 ounce mug of hot cocoa, how much do shares of Swiss Miss stock go up?
I’d expect that the soles of his feet, and any other high-wear areas, are more like thickened stale marshmallow. I don’t think his material properties are uniform, note that when he explodes, most of the material is gooey marshmallow cream and not puffy exterior mallow material. That might just be because he’s warm-blooded though, in which case his insides would be gooey until cooled down.
I assumed that a total protonic reversal was enough to melt said Marshmallow Man into gooey cream.
Oh yeah. I was in the process of figuring that out but then I had to leave the house. As far as I can tell, your math is spot-on for a human-sized figure scaled to 112.5 feet 
I was worried that my model was 10x bigger, but I manually double-checked the volume of the rectangular prism (can’t remember its exact dimensions, but it was basically as tall as he was, and as wide/long as his belly). So the volume calculator seems to be working as well. Maybe he IS just that much puffier! I was going to blow a human model up to the same scale to triple-check – and I still can if anyone really wants to see it – but I got lazy.
It would be interesting to model a more physically accurate version of the marshmallow man, taking into account the compression strength of unreinforced marshmallow, etc. But I suspect that would still be unconvincing because they were using Ancient Sumerian Math-gics anyway.
Me, too.
Go ahead, cross the beams!
I’ve seen Adam Savage on Mythbusters accurately recreate several movie props. He even briefly explained the process of taking measurements from screen caps. He claimed his calculations were very close to what the original was. Adam was a prop builder for a long time and knows his field.
It is possible to find the size of the Stay-Puft Man. If you were a prop maker for fifteen years.
It would be cool to have the Mythbusters answer this question. Except it’s not really a myth, so that ain’t gonna happen. But you guys have some pretty interesting answers. I’m getting a kick out of this!
I have a method:
Contact the studio, and obtain permission to borrow Sta-Puft, it is well known that the movie used a life-sized model for production.
Build a vat large enough to contain Sta-Puft.
Place Sta-Puft in the vat, and pour in a known quantity of liquid.
Subtract the known volume from the gradation shown.
Return Sta-Puft to the studio undamaged.
Have you watched the show recently? They’re almost exclusively ShitwesawonYouTubebusters now. All we’d have to do to get them interested is make a YouTube of someone calculating how much marshmallow fluff can be liberated via explosion and try to get them interested in reproducing the results.
