GarageCalc What 205/60R15 means
205 is the section width in millimeters (8.1 in). 60 is the aspect ratio: the sidewall is 60 percent of the width, so 205 × 0.60 = 123 mm (4.8 in). R is radial construction, and 15 is the wheel diameter in inches (381 mm). Stack two sidewalls on the wheel and you get the overall diameter: 381 + 2 × 123 = 627 mm, or 24.7 in.
A full marking adds a load index and speed rating after the size, for example 205/60R15 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 205/60R15
Going up one wheel size, the closest match is 225/50R16 at +0.7% diameter with a 113 mm sidewall instead of 123 mm. Going down one size, 195/70R14 is +0.3% with a taller 137 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 205/60R15 tire?
24.7 inches (627 mm) in overall diameter: the 15-inch wheel (381 mm) plus two 123 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 205/60R15 in inches?
24.7 x 8.1 R15: 24.7 inches tall, 8.1 inches wide, on a 15-inch wheel. The sidewall is 4.8 inches and the circumference is 77.6 inches, so the tire turns 817 times per mile.
What tire sizes are equivalent to 205/60R15?
Within 3 percent of the same diameter on the same 15-inch wheel: 185/65R15 (-0.9%), 195/65R15 (+1.2%), 195/60R15 (-1.9%); on a 16-inch wheel: 225/50R16 (+0.7%), 205/55R16 (+0.8%); on a 14-inch wheel: 195/70R14 (+0.3%), 185/70R14 (-2.0%). The percentage is the diameter change, which is also your speedometer error.
Can I use 215/60R15 instead of 205/60R15?
Dimensionally yes: 215/60R15 is 1.9% taller (+12 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 58.9 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 215 mm.