255/60R18 vs 265/60R18

265/60R18 is 0.47 in (12.0 mm) taller than 255/60R18, a +1.57% diameter difference. With the speedometer set for 255/60R18, an indicated 60 mph is 60.9 mph on 265/60R18.

Is this a safe swap?

Diameter difference +1.57%: within the ±3% guideline

By overall diameter alone, 265/60R18 falls inside the ±3% range commonly used as a guideline when replacing 255/60R18. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 255/60R18 (30.05 in) vs 265/60R18 (30.52 in)255/60R1830.05 in × 10.04 in265/60R1830.52 in × 10.43 in
Side profile and tread width, drawn to the same scale.
255/60R18 vs 265/60R18 differences
Measurement255/60R18265/60R18Difference% diff
Overall diameter30.05 in (763.2 mm)30.52 in (775.2 mm)+0.47 in (+12.0 mm)+1.57%
Sidewall height6.02 in (153.0 mm)6.26 in (159.0 mm)+0.24 in (+6.0 mm)+3.92%
Section width10.04 in (255.0 mm)10.43 in (265.0 mm)+0.39 in (+10.0 mm)+3.92%
Circumference94.40 in (2,397.7 mm)95.88 in (2,435.4 mm)+1.48 in (+37.7 mm)+1.57%
Revolutions per mile671661−10−1.55%
True speed with the speedometer calibrated for 255/60R18
IndicatedActual on 255/60R18Actual on 265/60R18Difference
30 mph30.0 mph30.5 mph+0.5 mph
60 mph60.0 mph60.9 mph+0.9 mph
75 mph75.0 mph76.2 mph+1.2 mph

Ride-height change: 265/60R18 raises the vehicle by 0.24 in (6.0 mm) at the axle (half the +12.0 mm diameter difference).

265/60R18 is 0.47 in taller than 255/60R18 and 10 mm wider, a 1.57% difference in overall diameter.

With the speedometer calibrated for 255/60R18, an indicated 60 mph is actually 60.9 mph on 265/60R18, and revolutions per mile change from 671 to 661.

Both sizes mount on 18-inch wheels.

Size pages

Other comparisons with 255/60R18

Other comparisons with 265/60R18

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.