Tire size comparisons
Tire Size Comparisons
Popular plus-size and replacement swaps, worked out from the size codes: diameter, width, sidewall, revolutions per mile, ground clearance and speedometer error at common speeds. Pick a pair or filter by size.
- 8 worked comparisons
- Speedometer tables
- Fit checklists
- Computed from the size code
Find a comparison
Popular size changes.
Up to 3%: within the common guideline3 to 5%: check clearance, expect speedometer errorOver 5%: usually needs a lift and recalibration
17-inch wheel265/70R17 → 285/70R17+3.5%+1.10 in diameter · 62.1 mph at 6017-inch wheel225/65R17 → 235/65R17+1.8%+0.51 in diameter · 61.1 mph at 6016-inch wheel245/75R16 → 265/75R16+3.9%+1.18 in diameter · 62.3 mph at 6020-inch wheel275/60R20 → 275/65R20+3.3%+1.08 in diameter · 62.0 mph at 6017-inch wheel265/70R17 → 35x12.50R17+10.7%+3.39 in diameter · 66.4 mph at 6017-inch wheel215/55R17 → 225/55R17+1.6%+0.43 in diameter · 61.0 mph at 6020-inch wheel275/55R20 → 285/55R20+1.4%+0.43 in diameter · 60.8 mph at 6017-inch wheel33x12.50R17 → 35x12.50R17+6.1%+2.00 in diameter · 63.6 mph at 60
No worked comparison for that size yet. Use the calculator below: it compares any two sizes.
Reading the numbers
What each figure tells you.
- Diameter changeThe percentage that decides speedometer error, gearing and how much taller the vehicle sits.
- Speedometer errorA taller tire makes the speedometer read low: at an indicated 60 you are going faster.
- Ground clearanceThe axle rises by half the change in diameter.
- Width per sideOn the same wheel, extra width is split between the inside and the outside.
Any two sizes
Need a different pair?
Type both sizes. Metric sizes such as 265/70R17 and P225/65R17 and flotation sizes such as 33x12.50R17 both work.
e.g. 265/70R17, P225/65R17 or 33x12.50R17
mph
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Figures are nominal geometry calculated from the size code. A tire’s real measured diameter varies by brand, model and tread depth; check the manufacturer’s spec sheet before you buy, and confirm clearance, load index and speed rating for your vehicle.
Free tools
265/70R17 → 285/70R17Tire Size CalculatorDiameter, sidewall, revolutions per mile, clearance and speedometer error.Open the calculator →7.5x17 +44 → 9x17 0Wheel Offset CalculatorBackspacing, how far the lip pokes out and how close the barrel gets.Open the calculator →113T → 2,535 lbs · 118 mphLoad Index & Speed RatingType the code from your sidewall and see what it means.Look up a code →