185/55R15 Tire Size Specifications & Compatible Vehicles

Overall Diameter

584.5 mm

Section Width

185 mm

Sidewall Height

101.8 mm

Circumference

1836.3 mm

Revs/Mile

876

Rim Diameter

15"

Alternative Tire Sizes

These tire sizes are within 3% overall diameter of 185/55R15 and may be used as replacements:

175/65R14 Safe 0.2% · -10mm · -1" rim 205/50R15 Safe 0.3% · +20mm · same rim 195/45R16 Safe 0.4% · +10mm · +1" rim 205/55R14 Safe 0.6% · +20mm · -1" rim 195/60R14 Safe 0.9% · +10mm · -1" rim 205/45R16 Safe 1.1% · +20mm · +1" rim 185/60R14 Safe 1.2% · same width · -1" rim 195/50R15 Safe 1.4% · +10mm · same rim 195/55R15 Caution 1.9% · +10mm · same rim 185/65R14 Caution 2.0% · same width · -1" rim 205/40R16 Caution 2.4% · +20mm · +1" rim 195/55R14 Caution 2.5% · +10mm · -1" rim

Understanding 185/55R15

The tire size 185/55R15 means the tire has a section width of 185mm, an aspect ratio of 55% (the sidewall height is 55% of the width), and fits a 15-inch rim.

Sidewall Height = 185 x 0.55 = 101.8 mm
Overall Diameter = (101.8 x 2) + (15 x 25.4) = 584.5 mm
Circumference = 584.5 x π = 1836.3 mm

With an aspect ratio of 55%, this is a standard-profile tire that balances ride comfort with handling precision. This profile range is the most common for passenger cars, crossovers, and light SUVs.

Choosing Replacement Tires

When replacing 185/55R15 tires, verify the size matches your vehicle's tire placard (typically found on the driver's door jamb or in the owner's manual). The NHTSA Tire Ratings Search tool lets you look up manufacturer load and speed ratings for specific tires.

Key factors beyond size: load index (must meet or exceed the vehicle's requirement), speed rating (must match or exceed the original specification), and seasonal type (all-season, summer, or winter) based on your driving conditions. The U.S. Tire Manufacturers Association recommends replacing all four tires at once, or at minimum in pairs on the same axle.