Last time I made bias binding two weeks ago I used the square method. I decided to do that again but needed help with calculations. I found this in my search: http://www.sew4home.com/tips-resources/sewing-tips-tricks/bias-binding-figuring-yardage-cutting-making-attaching
Sorry I can't shorten the link when I'm mobile blogging on the bus! Anyway, the steps were clear and easy.