Calculating Warp and Weft Needs

I was (finally) reading my Fall 2011 "Shuttle Spindle & Dyepot" magazine and found an interesting take on warp/weft calculations for a project. There are many good references on the web for doing these calcs. (for example: http://wovenfibers.com/thrums_calc.html or http://allfiberarts.com/2011/bl092599.htm)

What I liked in Marcy Petrini's approach is that it looked at yarn requirement from the yardage (as in square yard) perspective, not just the linear perspective. Marcy uses the square yard technique when doing on-the-fly estimates ... probably when in a shop lusting over a new find. While it seems to be most useful for weavers who are creating yardage, the article did cover how to think of any project in terms of square yards. I was not able to find the article online, but if you get SS&D have a look at the "Right from the Start" column.