A great deal depends on how the flour is measured. If you have a weight amount, always go with that.
If you fluff the flour in the container or sift it before measuring and don't pack it into the cup, it will be lighter. If you pack flour into a measuring cup, you could easily get a lot more than a cup into it. Because of these possible variations, weighing flour is always the best bet.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan