Looks like a solid little fire pit, but not for me. I would feel unsafe dumping a garbage can full of kerosene soaked phone books onto a pit that small.
I have one of those Weber grills. It's too small for a camp fire. Even if you are going for a small residential fire pit, it still needs to be able to hold a few standard sized 16" logs so maybe 24" minimum. At the campground where my camper is, they use semi trailer wheels with all the webbing cut out. That is about as small as I would want.