GarageCalc What 265/75R16 means
265 is the section width in millimeters (10.4 in). 75 is the aspect ratio: the sidewall is 75 percent of the width, so 265 × 0.75 = 199 mm (7.8 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 × 199 = 804 mm, or 31.6 in.
A full marking adds a load index and speed rating after the size, for example 265/75R16 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 265/75R16
Going up one wheel size, the closest match is 265/70R17 at -0.1% diameter with a 186 mm sidewall instead of 199 mm. No common 15-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 265/75R16 tire?
31.6 inches (804 mm) in overall diameter: the 16-inch wheel (406 mm) plus two 199 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 265/75R16 in inches?
31.6 x 10.4 R16: 31.6 inches tall, 10.4 inches wide, on a 16-inch wheel. The sidewall is 7.8 inches and the circumference is 99.4 inches, so the tire turns 637 times per mile.
What tire sizes are equivalent to 265/75R16?
Within 3 percent of the same diameter on the same 16-inch wheel: 275/70R16 (-1.6%); on a 17-inch wheel: 265/70R17 (-0.1%), 245/75R17 (-0.6%). The percentage is the diameter change, which is also your speedometer error.
Can I use 275/70R16 instead of 265/75R16?
Dimensionally yes: 275/70R16 is 1.6% shorter (-13 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 60.9 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.