Blankets & Quilts
Will the quilt just fit the top of the bed?
Will it hang over and by how much?
Will the quilt have to cover pillows at the top?
First, what size are the standard mattresses:
Crib 26" x 48"
Twin 39" x 75"
Double 54" x 75"
Queen 60" x 80"
King 78" x 80"
CAL King 72" x 84"
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".

Remember to allow for "shrinkage" when you do your quilting - most quilts lose about 5 percent due to quilting shrinkage. The more densely you place your hand or machine quilting, the more shrinkage you'll see happen.