GarageCalc What 235/65R16 means
235 is the section width in millimeters (9.3 in). 65 is the aspect ratio: the sidewall is 65 percent of the width, so 235 × 0.65 = 153 mm (6.0 in). R is radial construction, and 16 is the wheel diameter in inches (406 mm). Stack two sidewalls on the wheel and you get the overall diameter: 406 + 2 × 153 = 712 mm, or 28.0 in.
A full marking adds a load index and speed rating after the size, for example 235/65R16 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 235/65R16
Going up one wheel size, the closest match is 215/65R17 at -0.1% diameter with a 140 mm sidewall instead of 153 mm. Going down one size, 235/70R15 is -0.3% with a taller 165 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 235/65R16 tire?
28.0 inches (712 mm) in overall diameter: the 16-inch wheel (406 mm) plus two 153 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 235/65R16 in inches?
28.0 x 9.3 R16: 28.0 inches tall, 9.3 inches wide, on a 16-inch wheel. The sidewall is 6.0 inches and the circumference is 88.1 inches, so the tire turns 720 times per mile.
What tire sizes are equivalent to 235/65R16?
Within 3 percent of the same diameter on the same 16-inch wheel: 215/70R16 (-0.6%), 225/70R16 (+1.3%), 225/65R16 (-1.8%); on a 17-inch wheel: 215/65R17 (-0.1%), 235/60R17 (+0.3%); on a 15-inch wheel: 235/70R15 (-0.3%), 225/75R15 (+0.9%). The percentage is the diameter change, which is also your speedometer error.