265/70R17 vs 285/70R17
A calculated comparison of tire dimensions, speedometer change and clearance.
Last checked 12 October 2026Published by Sidewall GuideFormulas follow the Tire and Rim Association and ETRTO size conventions
3–5%: check clearance and speedometer
A similar diameter does not confirm fitment. Check load index, wheel width and clearance.
| Dimension | Current | New | Difference |
|---|---|---|---|
| Overall diameter | 31.61 in (803 mm) | 32.71 in (831 mm) | +1.10 in (+3.5%) |
| Section width | 10.43 in (265 mm) | 11.22 in (285 mm) | +0.79 in (+7.5%) |
| Sidewall height | 7.30 in (185 mm) | 7.85 in (199 mm) | +0.55 in (+7.5%) |
| Circumference | 99.29 in (2,522 mm) | 102.76 in (2,610 mm) | +3.46 in (+3.5%) |
| Revolutions per mile | 638 | 617 | −22 (−3.4%) |
Your speedometer
When your speedometer reads 30 / 45 / 60 / 75 mph, you are really doing …
| Speedometer reads | You are really doing |
|---|---|
| 30 mph | 31.0 mph |
| 45 mph | 46.6 mph |
| 60 mph | 62.1 mph |
| 75 mph | 77.6 mph |
Your speedometer will read low: you are going faster than it shows.
Your odometer will count 1,000 miles when you have driven 1,035 miles.
Clearance
Ride height: +0.55 in
Tread edge: +0.39 in further out and +0.39 in further in, on the same wheel offset
Ride height is half the diameter change. The width change splits equally to each side of the tire.
Fitment
Can I fit 285/70R17 instead of 265/70R17?
The calculated overall diameter changes by 1.10 in (3.5%). That is between 3% and 5%, so clearance and speedometer effects need careful review. This calculation cannot confirm fitment for a specific vehicle.
Plus-sizing
Other sizes near 265/70R17
Common sizes on the same wheel and on +1 and +2 wheels whose overall diameter stays within 3% of 265/70R17's 31.61 in.
Next step
Compare your own sizes
Use the calculator with both sizes prefilled, then change either value to match your vehicle or replacement tire.
Compare your own sizes