Ja, I know... it's like asking how long is a piece of string. I'm thinking of building a few Holtz Hauzens with the centers just loose tossed. Everyone knows that on a straight (rectangular) stack, 128 cu ft is a cord but in a circle, it would have to be based on the inside circumference. Add to that, that the circle generally gets smaller as you go up and then further complicate it by loose tossing the center with a crown on top and it's anyone's guess. In searching around, a loose tossed cord is said to be somewhere between 180 and 220 cu ft. It seems nobody can agree on a number, probably because the size and lengths of the splits are a factor as is the size of the container they are tossed into. 200 is probably a good number to go on. A 10 foot circle is obviously 120 inches, so based on 20 inch wood, the inside dimension is 100 inches which would have an inside circumference of 26.2 feet, so a foot tall perimeter would be around 43.7 cu ft. The loose tossed area inside would be 54.5 cu ft per foot of height. Based on the above, a 9 foot tall perimeter stack with plumb vertical sides would be around 3 cord. The loose stacked area inside would be 490.5 cu ft or somewhere around 2.5 cord. Now a HH almost always diminishes like a beehive, so how much to discount? Resorting to SWAG, I think maybe 4 cord in a 10 foot HH.