Background Image all out of scale.

I am setting up background in multiple view widows. But when I load the image into each view, the scale of the image is all different! Blender displays exact size of each image, so it has the information on size. Why does it display the images in different size? I have been rescaling background image by creating box mesh around the image and resizing scale of the other view to make it to right scale. Is this what you all do?

having the same problem. Did you ever find a better fix?

I found a post on here with this link
Its a web tool that computes the blender unit size you need to enter to make the bg image size up correctly in each viewport. It worked like a dream for me.