TireSizesFinder

225/75R16 vs 235/60R18

235/60R18 is 0.19 in (4.7 mm) shorter than 225/75R16, a −0.63% diameter difference. With the speedometer set for 225/75R16, an indicated 60 mph is 59.6 mph on 235/60R18.

Is this a safe swap?

Diameter difference −0.63%: under 1%

By overall diameter alone, 235/60R18 is a near match for 225/75R16; 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: 225/75R16 (29.29 in) vs 235/60R18 (29.10 in)225/75R1629.29 in × 8.86 in235/60R1829.10 in × 9.25 in
Side profile and tread width, drawn to the same scale.
225/75R16 vs 235/60R18 differences
Measurement225/75R16235/60R18Difference% diff
Overall diameter29.29 in (743.9 mm)29.10 in (739.2 mm)−0.19 in (−4.7 mm)−0.63%
Sidewall height6.64 in (168.8 mm)5.55 in (141.0 mm)−1.09 in (−27.7 mm)−16.44%
Section width8.86 in (225.0 mm)9.25 in (235.0 mm)+0.39 in (+10.0 mm)+4.44%
Circumference92.01 in (2,337.0 mm)91.43 in (2,322.3 mm)−0.58 in (−14.8 mm)−0.63%
Revolutions per mile689693+4+0.64%
True speed with the speedometer calibrated for 225/75R16
IndicatedActual on 225/75R16Actual on 235/60R18Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.5 mph−0.5 mph

Ride-height change: 235/60R18 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.7 mm diameter difference).

235/60R18 is 0.19 in shorter than 225/75R16 and 10 mm wider, a 0.63% difference in overall diameter.

With the speedometer calibrated for 225/75R16, an indicated 60 mph is actually 59.6 mph on 235/60R18, and revolutions per mile change from 689 to 693.

235/60R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 225/75R16.

Size pages

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