The secret formula is this: Max miles = 10,000 x (shoe size, american)/(runner weight in lbs)

But seriously, there are many factors here and shoes wear out differently for different people. My feet are wide and I retire most pairs of shoes because they just bust open eventually where the upper attaches to the sole (or the upper ruptures) near the widest part of my foot on the outside (near the base of the 5th metatarsal). This is usually 400-600 miles, but less for some frailer shoes. Wearing 2E shoes helps a bit but generally doesn't change the mode of failure. I'm a little below 160 lbs now; shoes usually wore out the same way for me when I was 20-30 lbs heavier but I didn't track mileage on them then.