GarageCalc What 265/70R17 means
265 is the section width in millimeters (10.4 in). 70 is the aspect ratio: the sidewall is 70 percent of the width, so 265 × 0.70 = 186 mm (7.3 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 × 186 = 803 mm, or 31.6 in.
A full marking adds a load index and speed rating after the size, for example 265/70R17 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 265/70R17
Going up one wheel size, the closest match is 265/65R18 at -0.1% diameter with a 172 mm sidewall instead of 186 mm. Going down one size, 265/75R16 is +0.1% with a taller 199 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.
Which cars come with 265/70R17
Typical factory fitments include Toyota 4Runner SR5, Ford F-150 XLT, Chevrolet Silverado 1500 and GMC Sierra 1500. Tire size changes with trim and wheel option, so confirm on the door-jamb placard before buying.
Frequently asked questions
How tall is a 265/70R17 tire?
31.6 inches (803 mm) in overall diameter: the 17-inch wheel (432 mm) plus two 186 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 265/70R17 in inches?
31.6 x 10.4 R17: 31.6 inches tall, 10.4 inches wide, on a 17-inch wheel. The sidewall is 7.3 inches and the circumference is 99.3 inches, so the tire turns 638 times per mile.
What tire sizes are equivalent to 265/70R17?
Within 3 percent of the same diameter on the same 17-inch wheel: 245/75R17 (-0.4%), 255/75R17 (+1.4%), 275/65R17 (-1.7%); on an 18-inch wheel: 265/65R18 (-0.1%), 245/70R18 (-0.3%); on a 16-inch wheel: 265/75R16 (+0.1%), 275/70R16 (-1.4%). The percentage is the diameter change, which is also your speedometer error.
Can I use 275/65R17 instead of 265/70R17?
Dimensionally yes: 275/65R17 is 1.7% shorter (-14 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 61.0 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 275 mm.