Tire Size Markings - What does it mean?

[Woody_PSD]

First, what does this mean:

275/70/R18 (got the R18 part), but apparently, the rim size also play into figuring out the actual tire size (32" or whatever)

Now based off those numbers how big "should" my tire be? I have also read that this might not be much of an exact science since those same numbers on a different tire could actually compute to something else.

My end goal to figure out how off my speedo is since it is running different tires than stock (what is the stock size? 265/70/R16 ?)

thanks for the help.

[pinkfloyd]

here's a link hope this helps Tire Size Calculator - tire & wheel plus sizing

[pinkfloyd]

here's another link that explains how to figure out your tire diameter 4Lo.com :: Metric Tire Size to Diameter in Inches Calculator

[Woody_PSD]

Awesome, thank you!

[skphotoimages]

Yes, I was going to pass on that first link. What I can tell you is the numbers in the tire size refer to its width, aspect ratio, and wheel diameter. "275/70R18" means the tire is 275 mm wide, has an aspect ratio (that is, the width divided by the height) of 70%.

[Woody_PSD]

Thank you! I should have known that all along, but ... you know how it goes