My rating system for books is at first going to seem a little backwards. It is a one to five scale. But my ratings are bookmarks.
1 bookmark = You can be dragged away from this book kicking and screaming, but you’ll read a few more pages every chance you get. You’ll probably finish this book in a day or two. Highest rating.
2 bookmarks = You can put this book down for the really important things, like eating, watching a favorite TV program, paying attention to your children. But, you will sneak a few more pages if you can. Probably a 2 to 4 day book.
3 bookmarks = You can put this book down and do other things that you would probably avoid if you were reading a more compelling book (laundry, kitty litter box, dishes, making dinner). You’ll probably finish this one within a week.
4 bookmarks = You can put this book down for at least a day or two at a time, but will probably still finish it in two weeks or so.
5 bookmarks = You can put this book down for a week or more at a time. You probably will finish it eventually, but you may even read another book in the meantime. Lowest rating.
I know it seems a little backwards at first, but it makes sense to me.