The hammock size is a tradeoff between weight and comfort.
Bigger is more comfortable, but heavier.
Sandy, from Miami area, who posts on the Hammockcamping forum, grew up in Venezuela, where they sleep in Hammocks as a normal practice. She led me to investigate Brazil type hammocks, which tend to be huge.
My current hammock measures full material width (58) by 12 feet before hemming. I tie it with a sheet bend knot, which I prefer to whipping or zipties. All three ways work.
I have been sleeping in it for over a month now.It's very comfortable. I lie at about a 30 degree angle to the center line.
After I tote the thing on an overnight hike, we'll see about cutting down size to minimize weight. When/if I do, I will go with JustJeffs figures for a starting point.