Tire size is located on the side wall for all tires...Image
Most tire sizes begin with a letter or letters that identify the type of vehicle. If there isn't a letter preceding the three-digit numeric portion of a tire size, it signifies the tire is a "Metric" size (also called "Euro-metric" because these sizes originated in Europe). Click here to see the chart of letters that start before the width numbers.
"P" Passanger Vehicle or P-metric
"185" Width of the tire measured in millimeters from sidewall to sidewall...image
"65" The 65 indicates that this tire size's sidewall height (from rim to tread) 65% of its section width...image
"R/RF" R signifies Radial. RF signifies Run Flat...image
"15" Double digit number at the end is the Wheel Size...image