Well, the rule of the thumb is to take the width of your binding and " double it" to figure out how much to overlap. (For example 2.5in binding would be a 5in overlap) But this didn't do squat for me, because it would lay flat but when I got to the end, there would always be some bunching. Then I actually got a walking foot, and my binding looks beautiful when I started binding with a walking foot. My binding looks perfect now.