265/70R16 vs 275/60R18

275/60R18 is 0.39 in (9.8 mm) taller than 265/70R16, a +1.26% diameter difference. With the speedometer set for 265/70R16, an indicated 60 mph is 60.8 mph on 275/60R18.

Is this a safe swap?

Diameter difference +1.26%: within the ±3% guideline

By overall diameter alone, 275/60R18 falls inside the ±3% range commonly used as a guideline when replacing 265/70R16. 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.

265/70R16 vs 275/60R18 differences
Measurement	265/70R16	275/60R18	Difference	% diff
Overall diameter	30.61 in (777.4 mm)	30.99 in (787.2 mm)	+0.39 in (+9.8 mm)	+1.26%
Sidewall height	7.30 in (185.5 mm)	6.50 in (165.0 mm)	−0.81 in (−20.5 mm)	−11.05%
Section width	10.43 in (265.0 mm)	10.83 in (275.0 mm)	+0.39 in (+10.0 mm)	+3.77%
Circumference	96.15 in (2,442.3 mm)	97.36 in (2,473.1 mm)	+1.21 in (+30.8 mm)	+1.26%
Revolutions per mile	659	651	−8	−1.24%

True speed with the speedometer calibrated for 265/70R16
Indicated	Actual on 265/70R16	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	75.9 mph	+0.9 mph

Ride-height change: 275/60R18 raises the vehicle by 0.19 in (4.9 mm) at the axle (half the +9.8 mm diameter difference).

275/60R18 is 0.39 in taller than 265/70R16 and 10 mm wider, a 1.26% difference in overall diameter.

With the speedometer calibrated for 265/70R16, an indicated 60 mph is actually 60.8 mph on 275/60R18, and revolutions per mile change from 659 to 651.

275/60R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 265/70R16.

Size pages

Other comparisons with 265/70R16

Other comparisons with 275/60R18

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