TireSizesFinder

265/70R16 vs 245/65R18

245/65R18 is 0.07 in (1.7 mm) shorter than 265/70R16, a −0.22% diameter difference. With the speedometer set for 265/70R16, an indicated 60 mph is 59.9 mph on 245/65R18.

Is this a safe swap?

Diameter difference −0.22%: under 1%

By overall diameter alone, 245/65R18 is a near match for 265/70R16; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 265/70R16 (30.61 in) vs 245/65R18 (30.54 in)265/70R1630.61 in × 10.43 in245/65R1830.54 in × 9.65 in
Side profile and tread width, drawn to the same scale.
265/70R16 vs 245/65R18 differences
Measurement265/70R16245/65R18Difference% diff
Overall diameter30.61 in (777.4 mm)30.54 in (775.7 mm)−0.07 in (−1.7 mm)−0.22%
Sidewall height7.30 in (185.5 mm)6.27 in (159.3 mm)−1.03 in (−26.2 mm)−14.15%
Section width10.43 in (265.0 mm)9.65 in (245.0 mm)−0.79 in (−20.0 mm)−7.55%
Circumference96.15 in (2,442.3 mm)95.94 in (2,436.9 mm)−0.21 in (−5.3 mm)−0.22%
Revolutions per mile659660+1+0.22%
True speed with the speedometer calibrated for 265/70R16
IndicatedActual on 265/70R16Actual on 245/65R18Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.9 mph−0.1 mph
75 mph75.0 mph74.8 mph−0.2 mph

Ride-height change: 245/65R18 lowers the vehicle by 0.03 in (0.8 mm) at the axle (half the −1.7 mm diameter difference).

245/65R18 is 0.07 in shorter than 265/70R16 and 20 mm narrower, a 0.22% difference in overall diameter.

With the speedometer calibrated for 265/70R16, an indicated 60 mph is actually 59.9 mph on 245/65R18, and revolutions per mile change from 659 to 660.

245/65R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 265/70R16.

Size pages

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