If you're like me, when you're in a fabric shop and discover a fabric you "have to have" but have no idea what length of fabric you need to make what you want, I found a really helpful solution. These are "How much fabric" reference cards from GwynHug. Great purse sized cards make it a very handy reference.
When ordering note that there are imperial and metric versions. After ordering, they arrived in a flash and are now sitting in my handbag for the next purchase.