Home275/70R18 vs 285/65R18

275/70R18 vs 285/65R18

The 285/65R18 is 32.59 in tall: 0.57 in (1.7%) shorter than the 275/70R18 at 33.16 in. At an indicated 60 mph you'd be doing 59.0 mph.The 285/65R18 is 827.7 mm tall: 14.5 mm (1.7%) shorter than the 275/70R18 at 842.2 mm. At an indicated 100 km/h you'd be doing 98.3 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

Width and aspect ratio both change (275/70 to 285/65). The 285/65R18 is 0.39 in wider, but each sidewall is 0.29 in shorter, so it ends up 0.57 in shorter overall.

Makers' own measured diameters run 33.19 to 33.62 in for the 275/70R18 and 32.56 to 32.83 in for the 285/65R18, against the calculated 33.16 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 275/70R18 reads high on the 285/65R18: an indicated 60 mph is a true 59.0 mph.A speedometer that read true on the 275/70R18 reads high on the 285/65R18: an indicated 100 km/h is a true 98.3 km/h.

The odometer records about 10,180 miles for every 10,000 you drive.The odometer records about 10,180 km for every 10,000 you drive.

Ground clearance and size class

Ground clearance at the axle drops by 0.29 in: half the diameter change, unloaded.Ground clearance at the axle drops by 7.3 mm: half the diameter change, unloaded. By calculated diameter both are 33-inch tires.

See every 33-inch size in metric.

Other comparisons with these sizes

• 275/65R18 vs 285/65R18

275/70R18 in inches.

Compare other sizes in the calculator