TireSizesFinder

235/60R16 vs 215/55R18

215/55R18 is 0.21 in (5.3 mm) taller than 235/60R16, a +0.77% diameter difference. With the speedometer set for 235/60R16, an indicated 60 mph is 60.5 mph on 215/55R18.

Is this a safe swap?

Diameter difference +0.77%: under 1%

By overall diameter alone, 215/55R18 is a near match for 235/60R16; 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: 235/60R16 (27.10 in) vs 215/55R18 (27.31 in)235/60R1627.10 in × 9.25 in215/55R1827.31 in × 8.46 in
Side profile and tread width, drawn to the same scale.
235/60R16 vs 215/55R18 differences
Measurement235/60R16215/55R18Difference% diff
Overall diameter27.10 in (688.4 mm)27.31 in (693.7 mm)+0.21 in (+5.3 mm)+0.77%
Sidewall height5.55 in (141.0 mm)4.66 in (118.3 mm)−0.90 in (−22.7 mm)−16.13%
Section width9.25 in (235.0 mm)8.46 in (215.0 mm)−0.79 in (−20.0 mm)−8.51%
Circumference85.14 in (2,162.7 mm)85.80 in (2,179.3 mm)+0.66 in (+16.7 mm)+0.77%
Revolutions per mile744738−6−0.76%
True speed with the speedometer calibrated for 235/60R16
IndicatedActual on 235/60R16Actual on 215/55R18Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.5 mph+0.5 mph
75 mph75.0 mph75.6 mph+0.6 mph

Ride-height change: 215/55R18 raises the vehicle by 0.10 in (2.7 mm) at the axle (half the +5.3 mm diameter difference).

215/55R18 is 0.21 in taller than 235/60R16 and 20 mm narrower, a 0.77% difference in overall diameter.

With the speedometer calibrated for 235/60R16, an indicated 60 mph is actually 60.5 mph on 215/55R18, and revolutions per mile change from 744 to 738.

215/55R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 235/60R16.

Size pages

Other comparisons with 235/60R16

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