Speedometer correction

[HiTechRedneck]

After changing to Nitto 35 12.5 X 17's on Method NV's I need to correct the speedometer using revolutions per mile on the SCT tuner (which I can do)
Here's my question - it looks like my 35's are actually 34" diameter & not 35!
Has anyone verified this to be correct?
If they are actually 35 I need 577 revs per mile
At 34 it needs 593

Thanks!!

 

[tbone]

i believe the stock tires are 34.5's