mild problems

Those of you who know me know that I could open a yarn store with the yarn presently in this house. I'm having a real problem with this. I have two or three patterns for vests that I really, really want to make. I have pulled out the yarns (color coded, of course) and tried to find enough skeins or balls that really go well together to make something. I have a real problem here. One pattern gives me yardage. I have more than enough, but it is not the right size to measure this way. I don't do well in math, so never learned this part. Patterns often give a particular yarn and don't specify it's loft or diameter, and I don't know how to translate this. This yarn , of which I have more than enough, I can hold in one hand. No way that is going to cover this body - no way atall. When I make shawls, I just start with what I like and change as the mood hits me. I don't think this will work with a vest. Somehow. Ideas, anyone? And remember, I don't do math.