Andri,
Yes, attach the binding 1/4" from the edge of the top. Trim with 1/4" additional batting beyond the edge of the top. Trim THAT as necessary as you attach to the back of the quilt. One thing that pops up at quilt shows and fairs is full bindings. This makes sure that you have that full binding.
The lady the taught me this trick leaves the entire amount in the binding. Sometimes it seems to me to be too full (depends on the batting used), but she wins the ribbons. I'm not going to argue....... :!: