GarageCalc What 265/60R20 means
265 is the section width in millimeters (10.4 in). 60 is the aspect ratio: the sidewall is 60 percent of the width, so 265 × 0.60 = 159 mm (6.3 in). R is radial construction, and 20 is the wheel diameter in inches (508 mm). Stack two sidewalls on the wheel and you get the overall diameter: 508 + 2 × 159 = 826 mm, or 32.5 in.
A full marking adds a load index and speed rating after the size, for example 265/60R20 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 265/60R20
Going up one wheel size, the closest match is 275/50R21 at -2.1% diameter with a 138 mm sidewall instead of 159 mm. No common 19-inch size stays within 3 percent either. 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 265/60R20 tire?
32.5 inches (826 mm) in overall diameter: the 20-inch wheel (508 mm) plus two 159 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 265/60R20 in inches?
32.5 x 10.4 R20: 32.5 inches tall, 10.4 inches wide, on a 20-inch wheel. The sidewall is 6.3 inches and the circumference is 102.2 inches, so the tire turns 620 times per mile.
What tire sizes are equivalent to 265/60R20?
Within 3 percent of the same diameter on the same 20-inch wheel: 285/55R20 (-0.5%), 275/60R20 (+1.5%), 275/55R20 (-1.9%); on a 21-inch wheel: 275/50R21 (-2.1%). The percentage is the diameter change, which is also your speedometer error.
Can I use 275/60R20 instead of 265/60R20?
Dimensionally yes: 275/60R20 is 1.5% taller (+12 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 59.1 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.