GarageCalc What 175/65R13 means
175 is the section width in millimeters (6.9 in). 65 is the aspect ratio: the sidewall is 65 percent of the width, so 175 × 0.65 = 114 mm (4.5 in). R is radial construction, and 13 is the wheel diameter in inches (330 mm). Stack two sidewalls on the wheel and you get the overall diameter: 330 + 2 × 114 = 558 mm, or 22.0 in.
A full marking adds a load index and speed rating after the size, for example 175/65R13 91V. Those two codes set how much weight and speed the tire is certified for; look them up in the load index chart and the speed rating chart.
Plus and minus sizing from 175/65R13
Going up one wheel size, the closest match is 155/65R14 at -0.1% diameter with a 101 mm sidewall instead of 114 mm. Going down one size, 155/80R12 is -0.9% with a taller 124 mm sidewall for more comfort and pothole margin. Anything inside 3 percent keeps the speedometer, ABS and gearing effectively stock; the comparison calculator shows the full speedometer table for any pair.
Frequently asked questions
How tall is a 175/65R13 tire?
22.0 inches (558 mm) in overall diameter: the 13-inch wheel (330 mm) plus two 114 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 175/65R13 in inches?
22.0 x 6.9 R13: 22.0 inches tall, 6.9 inches wide, on a 13-inch wheel. The sidewall is 4.5 inches and the circumference is 69.0 inches, so the tire turns 919 times per mile.
What tire sizes are equivalent to 175/65R13?
Within 3 percent of the same diameter on the same 13-inch wheel: 165/70R13 (+0.6%), 185/60R13 (-1.0%), 155/70R13 (-1.9%); on a 14-inch wheel: 155/65R14 (-0.1%), 185/55R14 (+0.3%); on a 12-inch wheel: 155/80R12 (-0.9%). The percentage is the diameter change, which is also your speedometer error.
Can I use 185/60R13 instead of 175/65R13?
Dimensionally yes: 185/60R13 is 1.0% shorter (-6 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 60.6 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 185 mm.