Tire Size Box

Tire size comparison

Enter your current size and the one you're considering. Works with metric (265/70R17) and flotation (33x12.50R17) sizes. 6,591 common comparisons also have their own pages.

With 285/70R17 tires, when your speedometer says 60 mph you are really going

62.1 mph

285/70R17 is +1.10 inches (+3.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/70R17285/70R17Difference%
Overall diameter31.61"32.71"+1.10"+3.5%
Section width10.43"11.22"+0.79"+7.5%
Sidewall height7.30"7.85"+0.55"+7.5%
Circumference99.29"102.76"+3.46"+3.5%
Revolutions per mile638.1616.6−21.5−3.4%

Popular comparisons

Questions

What is the 3% rule for tire sizes?
Keep a replacement tire within 3% of the original overall diameter. Inside that range the speedometer error is small and ABS, traction control and gearing behave as designed.
How do I know if a bigger tire will fit?
Check the extra height (half the diameter difference is how much closer the tire gets to the fender) and the extra width against your wheel well, suspension and steering lock. A test fit or a shop check is the safest way.
Does tire size affect gas mileage?
Bigger and wider tires are usually heavier and have more rolling resistance, which lowers fuel economy. The odometer also under-counts with taller tires, so calculated mpg looks worse than it is.