I used to use 2.5 but found it to be too large when I turned it to the back to hand stitch. So I went to 2.25 and that seems to work best for me. I use a 1.4 inch seam to attach the binding to the front of my quilts. I double mine so they will last longer. Most of my quilts have been for the younger generation so figured they'd be dragging it around.