TireSizesFinder

215/85R16 vs 245/65R18

245/65R18 is 0.15 in (3.8 mm) taller than 215/85R16, a +0.49% diameter difference. With the speedometer set for 215/85R16, an indicated 60 mph is 60.3 mph on 245/65R18.

Is this a safe swap?

Diameter difference +0.49%: under 1%

By overall diameter alone, 245/65R18 is a near match for 215/85R16; 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: 215/85R16 (30.39 in) vs 245/65R18 (30.54 in)215/85R1630.39 in × 8.46 in245/65R1830.54 in × 9.65 in
Side profile and tread width, drawn to the same scale.
215/85R16 vs 245/65R18 differences
Measurement215/85R16245/65R18Difference% diff
Overall diameter30.39 in (771.9 mm)30.54 in (775.7 mm)+0.15 in (+3.8 mm)+0.49%
Sidewall height7.19 in (182.8 mm)6.27 in (159.3 mm)−0.93 in (−23.5 mm)−12.86%
Section width8.46 in (215.0 mm)9.65 in (245.0 mm)+1.18 in (+30.0 mm)+13.95%
Circumference95.47 in (2,425.0 mm)95.94 in (2,436.9 mm)+0.47 in (+11.9 mm)+0.49%
Revolutions per mile664660−3−0.49%
True speed with the speedometer calibrated for 215/85R16
IndicatedActual on 215/85R16Actual on 245/65R18Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.3 mph+0.3 mph
75 mph75.0 mph75.4 mph+0.4 mph

Ride-height change: 245/65R18 raises the vehicle by 0.07 in (1.9 mm) at the axle (half the +3.8 mm diameter difference).

245/65R18 is 0.15 in taller than 215/85R16 and 30 mm wider, a 0.49% difference in overall diameter.

With the speedometer calibrated for 215/85R16, an indicated 60 mph is actually 60.3 mph on 245/65R18, and revolutions per mile change from 664 to 660.

245/65R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 215/85R16.

Size pages

Other comparisons with 215/85R16

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