Reading of Tyre data

185/60R14


185– Width of Tyre in millimeter 
14– Diameter of rim in inches
R– Radial construction of Tyre
60– Percentage ratio of (Side wall of Tyre)/(Width of Tyre)
=> 60/100=side wall/185
=>side wall=111 mm
Radius of Tyre=side wall+radius of rim
R=111+177.8 (7 inches)
R=288.8 mm

Try this yourself-175/65R14