Home275/65R18 vs 285/65R18

275/65R18 vs 285/65R18

The 285/65R18 is 32.59 in tall: 0.52 in (1.6%) taller than the 275/65R18 at 32.07 in. At an indicated 60 mph you'd be doing 61.0 mph.The 285/65R18 is 827.7 mm tall: 13.0 mm (1.6%) taller than the 275/65R18 at 814.7 mm. At an indicated 100 km/h you'd be doing 101.6 km/h.

By David Owen. Published 3 November 2026.

in, mphmm, km/h

Each figure is rounded separately, so related figures can differ in the last digit.

These are size-code figures only. Whether a size fits, clears and carries your load depends on your vehicle and the tire, so check with a tire shop.

What changes

Only the section width changes, from 10.83 in to 11.22 in. The aspect ratio is a percentage of the width, so each sidewall grows with it, by 0.25 in, and the 285/65R18 ends up 0.52 in taller overall.

Makers' own measured diameters run 32.09 to 32.32 in for the 275/65R18 and 32.56 to 32.83 in for the 285/65R18, against the calculated 32.07 in and 32.59 in. Real tires vary by brand and tread design; the figures in the table come from the size code alone.

Speedometer and odometer

A speedometer that read true on the 275/65R18 reads low on the 285/65R18: an indicated 60 mph is a true 61.0 mph.A speedometer that read true on the 275/65R18 reads low on the 285/65R18: an indicated 100 km/h is a true 101.6 km/h.

The odometer records about 9,840 miles for every 10,000 you drive.The odometer records about 9,840 km for every 10,000 you drive.

Ground clearance and size class

Ground clearance at the axle rises by 0.26 in: half the diameter change, unloaded.Ground clearance at the axle rises by 6.5 mm: half the diameter change, unloaded. By calculated diameter the 275/65R18 is a 32-inch tire and the 285/65R18 a 33-inch tire.

See every 32-inch and 33-inch size in metric.

Same change, other sizes

5 other searched pairs make the same change in diameter, width and sidewall:

• 265/65R18 vs 275/65R18
• 275/65R20 vs 285/65R20
• 285/65R20 vs 295/65R20
• 225/65R17 vs 235/65R17
• 195/65R15 vs 205/65R15

Other comparisons with these sizes

• 265/60R18 vs 275/65R18
• 275/70R18 vs 285/65R18

Compare other sizes in the calculator