Okay @DaygoErm
My hood--it was cut 20 inches wide, 40 inches long--the fabric folds to be a 20 x 20 square. The seam goes down the back. Because I have a fairly small noggin, I did shape mine a little so that its not so wide across the face, but kept the roominess in the back/sides. So in comparing our measurements--my hood is about 4 inches deeper across the top, and about 3 inches in length from the top of the hood to the neck.
Like I said, I use the feather weight boning--and it keeps the round shape really well--I didn't pose that for the picture, its just the way the hood lays!
31910663_10211820624736116_9056138594602713088_n by Lesley Farquhar, on Flickr
31880661_10211820624816118_6676313480930263040_n by Lesley Farquhar, on Flickr