Full Circle Panuela ?

[Martin Moser]

I've read somewhere that a sagum was to but doubled, which would have meant 3x3=9m of wool. Coincidence?
Mine's 'just' 3x1.5, which is heavy enough for me. But if I were travelling along a snowy road in winter, I guess I'd be very happy with it.

No. You are talking about square meters. 9 square meters. A full circle paenula with above measures would have a little more than 7 square meters.
What I meant was the length of the lower edge of the paenula. This would become more than 9m long.
If you want to have more material because of your segmentata or so, you would need the material further up, mostly in the area of your chest and shoulders, lots of material at the height of your knees or ankles wouldn't help. If anything you would have to make the circle even bigger, for the paenula to still come down as far as before, because having a "roomier" shoulder area would result in the lower edge being drawn up.
If you want more warmth, you would want a 2nd layer, and that mostly around your torse, not many meters of wool falling into lots of folds at the lower end around your ankles (i.e. what you get when you have a full circle).
Actually, ca. 1.3 square meters of a 1.5m radius paenula with 7 square meters (so almost 1/5th) go into the lower 20cm edge of that paenula, for little effect.