265/65R17 vs 275/60R18

275/60R18 is 0.43 in (10.9 mm) taller than 265/65R17, a +1.40% diameter difference. With the speedometer set for 265/65R17, an indicated 60 mph is 60.8 mph on 275/60R18.

Is this a safe swap?

Diameter difference +1.40%: within the ±3% guideline

By overall diameter alone, 275/60R18 falls inside the ±3% range commonly used as a guideline when replacing 265/65R17. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

265/65R17 vs 275/60R18 differences
Measurement	265/65R17	275/60R18	Difference	% diff
Overall diameter	30.56 in (776.3 mm)	30.99 in (787.2 mm)	+0.43 in (+10.9 mm)	+1.40%
Sidewall height	6.78 in (172.3 mm)	6.50 in (165.0 mm)	−0.29 in (−7.2 mm)	−4.21%
Section width	10.43 in (265.0 mm)	10.83 in (275.0 mm)	+0.39 in (+10.0 mm)	+3.77%
Circumference	96.02 in (2,438.8 mm)	97.36 in (2,473.1 mm)	+1.35 in (+34.2 mm)	+1.40%
Revolutions per mile	660	651	−9	−1.38%

True speed with the speedometer calibrated for 265/65R17
Indicated	Actual on 265/65R17	Actual on 275/60R18	Difference
30 mph	30.0 mph	30.4 mph	+0.4 mph
60 mph	60.0 mph	60.8 mph	+0.8 mph
75 mph	75.0 mph	76.1 mph	+1.1 mph

Ride-height change: 275/60R18 raises the vehicle by 0.21 in (5.5 mm) at the axle (half the +10.9 mm diameter difference).

275/60R18 is 0.43 in taller than 265/65R17 and 10 mm wider, a 1.40% difference in overall diameter.

With the speedometer calibrated for 265/65R17, an indicated 60 mph is actually 60.8 mph on 275/60R18, and revolutions per mile change from 660 to 651.

275/60R18 mounts on a 18-inch wheel, a plus-1 fitment from the 17-inch wheel of 265/65R17.

Size pages

Other comparisons with 265/65R17

Other comparisons with 275/60R18

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.