Thanks, all, for your advice.
I've been busy since my querry. I found the calculators y'all mentioned. Now all this mathaphobic brain has to do is try to follow the directions.
I am trying to figure out if I have enough yarn for a simple T shirt style sweater with 3/4 length sleeves and a wider, round neck. I don't want to start it and discover I don't have enough. I hand dyed the wool last summer with plans to start on it in the fall. Well . . . that didn't happen. Now, I'm not sure.