Challenge Rug Progress...

I have been working on the antique challenge rug here and there...I made a mistake first of all, I didn't have a piece of linen left that was actually big enough for this design, but i am going to be keeping this rug, so I am just going to have to do a super thin type binding on the rug, or just sew binding fabric around the very edges and fold under, and there is still only going to be a row for the background in the very top portion of the rug where the quilt type star is. Secondly, because I knew I didn't have a large enough piece of linen left, I didn't enlarge the pattern quite as big as I should have, and i had to re-draw a few things, which i should of spaced further apart before drawing on the linen...Oh well, live and learn and keep learnin'.....lol And...I am just so duhhhh..i didn't even make sure I had enough of the browns I started the tree on the left with, so I am really Mickey mousing the colors on this....How do you figure the amount of wool you need for a rug? As far as the individual elements in the design go ?? There has to be a better way than mine...I just eyeball it, look at the little bit of wool I have and say, yep that should be enough.....lol It's been a weird week last week and so far this week, as my 18 year old just started a job at a McDonald's right down the road not too far, but they have her doing all weird hours, so I've been running back and forth alot, dropping off and picking up... For me it's weird as I've gone from hermit and never behind the wheel to in and out almost every day since last Monday..It's good for me, yes, but I get so involved in projects or house cleaning and forget when it gets really close to the time to pick her up, but she does text me to remind me, cause she KNOWS how I am....lol