["Also, don't forget to think about the height of the mattress as well. This will affect how much overhang you choose to add. Standard mattresses are 8-10" thick, but some extra thick ones may be as high as 16-18" "]
many mattresses and boxes are even taller than that. are they for the princess who slept on the pea? and if you have a side rail, as i do, then you also have to think about that when you plan your drop. for my queen bed, with a 60" width, i need a 98" quilt to hit the top of the rail. isn't that ridiculous? otherwise, the boxspring shows.