GarageCalc What 215/65R17 means
215 is the section width in millimeters (8.5 in). 65 is the aspect ratio: the sidewall is 65 percent of the width, so 215 × 0.65 = 140 mm (5.5 in). R is radial construction, and 17 is the wheel diameter in inches (432 mm). Stack two sidewalls on the wheel and you get the overall diameter: 432 + 2 × 140 = 711 mm, or 28.0 in.
A full marking adds a load index and speed rating after the size, for example 215/65R17 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 215/65R17
Going up one wheel size, the closest match is 235/55R18 at +0.6% diameter with a 129 mm sidewall instead of 140 mm. Going down one size, 235/65R16 is +0.1% with a taller 153 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 215/65R17 tire?
28.0 inches (711 mm) in overall diameter: the 17-inch wheel (432 mm) plus two 140 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 215/65R17 in inches?
28.0 x 8.5 R17: 28.0 inches tall, 8.5 inches wide, on a 17-inch wheel. The sidewall is 5.5 inches and the circumference is 88.0 inches, so the tire turns 720 times per mile.
What tire sizes are equivalent to 215/65R17?
Within 3 percent of the same diameter on the same 17-inch wheel: 235/60R17 (+0.4%), 225/60R17 (-1.3%), 225/65R17 (+1.8%); on an 18-inch wheel: 235/55R18 (+0.6%), 225/55R18 (-0.9%); on a 16-inch wheel: 235/65R16 (+0.1%), 215/70R16 (-0.5%). The percentage is the diameter change, which is also your speedometer error.
Can I use 225/60R17 instead of 215/65R17?
Dimensionally yes: 225/60R17 is 1.3% shorter (-10 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 60.8 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 225 mm.