Oh, well, if it’s on the internet, then….
Look, I understand that tire section width will vary with wheel width for a given tire, but common sense should tell you that the exact amount of change will depend on the height of the sidewall and on the difference between the section width and the rim width. This can’t be a single number for ALL tires and ALL rims. In any case, my point above still stands. With my 6″ wide wheels and 205/70 tires, I have more than 1/2″ clearance to the fender lip.