Respectfully request tire height 275/60 R15 'S

If you can't find it on a chart, take a piece of twine, wrap it around the tire, carefully mark it where it comes together, get your tape measure out and measure what you wrapped around the tire. Now you can get all twisted up trying to remember High School Geometry....

Circumference is equal to pi times Diameter (pi is equal to 3.1415) you've got Circumference, that is the measurement of twine, Diameter is gonna be: circumference divided by pi

They never told us in school that math would be good for working on cars......