NateJG

10/32" = 100% = New Tire
2/32" = 0% (aka Worn Out)
10 - 2 = 8 (8/32" useful)
8/32" of available (legal) wear available (in the New tire)
3/32" / 8/32" = 37.5% used thus far
Therefore:
5/32" remains (until worn to the point of "legally worn out")
So: 5/32" (remaining) / 8/32" (originally available) = 62.5% life remains

NateJG

Or, to get back to my first post...

Your tire is now 29.0125" in diameter vs the 29.2" diameter when new.

3/32" off each side = 6/32" change in diameter of the tire = 0.1875" less in diameter.

Meaning your tire is at 99.357877% of the diameter of a New tire.

In my business, we called that "Decimal Dust".

And for this, someone suggests that you shave it? (Or, assuming they're wearing at the same rate, change out the other three tires with 62.5% tire life remaining?)