If you ever recover furniture, you may know that estimating fabric can be a chore. Thankfully a variety of yardage charts for common styles of chairs and couches. A PDF version can be found at http://www.m-sfabrics.com/ms_pdf/ydg_chrt.pdf.
DI Upholstery has a separate website for chairs and couches which you can get to at http://www.diyupholsterysupply.com/ChairChart.html
Has a variety of chairs, couches, foot stools and the like as well as slide shows about the business.