How many revolutions per mile is 33x12.50R17?

The wheel size makes no difference at all

33x12.50R15, 33x12.50R16, 33x12.50R17, 33x12.50R18 and 33x12.50R20 all turn 611.2 times to cover a mile. Every one of them is 33.00 in in overall diameter by definition, and rotation count depends on nothing but overall diameter. A 15-inch wheel with a 9.00 in sidewall and a 20-inch wheel with a 6.50 in sidewall roll exactly the same distance per turn.

This is easy to say and surprisingly hard to believe when the two tires are standing next to each other looking nothing alike.

Which means a metric size can match it exactly too

275/60R20 turns 611.3 times per mile. One tenth of a rotation in six hundred separates it from a flotation 33 — a difference no instrument on a vehicle could act on, despite one tire being 1.67 in wider than the other. Rotation count is blind to everything except height.

255/80R17 is another near-match at 610.0, and narrower again at 10.04 in. Three tires with almost nothing in common visually, all inside two rotations per mile of each other.

What the number is doing for you

611.2 is the figure that makes a fitment question computable. Divide any other size's count by it and the result is the proportional change: against a 265/70R17 at 638.1 the ratio gives 4.41%. That single percentage covers what the speedometer is out by, what the odometer is out by, and how much the axle ratio would have to move to undo it.

Geometric, and slightly optimistic

The count is derived from the size code rather than measured on a rolling road. A loaded tire deflects at the contact patch and travels a little less per turn than its free circumference implies, so a manufacturer's measured figure for a real 33x12.50R17 will read somewhat above 611.2. For comparing two sizes the geometric figure is the right tool, because both sides of the comparison are computed the same way. Put any two into the tool and both counts appear side by side.