265/70R18 vs 275/70R18

275/70R18 is 0.6" taller than 265/70R18 (1.7%)

Diameter difference+1.69%diameter 32.61" → 33.16"
265/70R18275/70R18
265/70R18275/70R18Difference
Overall diameter32.61"33.16"+0.55"
Section width10.43"10.83"+0.39"
Sidewall height7.30"7.58"+0.28"
Circumference102.4"104.2"+1.7"
Revolutions per mile619608−10
Wheel diameter18"18"±0"

Speedometer

ShowsActualDiff
30 mph30.5 mph+0.5
45 mph45.8 mph+0.8
60 mph61.0 mph+1.0
70 mph71.2 mph+1.2
80 mph81.4 mph+1.4

Gear ratio to match

CurrentEquivalent
3.423.48
3.553.61
3.733.79
4.104.17

275/70R18 is 0.55" taller than 265/70R18, a +1.69% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.28" (half the diameter change), and the tire needs 0.28" more room above it.

275/70R18 is 0.39" wider. On the same wheel offset about half of that, 0.20", moves toward the suspension and half toward the fender.

Both fit a 18" wheel; the sidewall is 0.28" taller on 275/70R18.

Details: 265/70R18 in inches · 275/70R18 in inches · change sizes in the calculator

FAQ

What is the difference between 265/70R18 and 275/70R18?

275/70R18 is 0.55" taller (+1.69%) and 0.39" wider than 265/70R18.

Will 275/70R18 change my speedometer?

Yes, by +1.69%. When the speedometer shows 60 mph you would be going 61.0 mph.

Can I replace 265/70R18 with 275/70R18?

Often yes: the diameter change of +1.7% is within the common 3% guideline. Check the load index, speed rating and clearance.