185/70R15 Tire Size Specifications & Compatible Vehicles

Overall Diameter

640.0 mm

Section Width

185 mm

Sidewall Height

129.5 mm

Circumference

2010.6 mm

Revs/Mile

800

Rim Diameter

15"

Alternative Tire Sizes

These tire sizes are within 3% overall diameter of 185/70R15 and may be used as replacements:

195/60R16 Safe 0.1% · +10mm · +1" rim 205/70R14 Safe 0.4% · +20mm · -1" rim 205/50R17 Safe 0.5% · +20mm · +2" rim 175/80R14 Safe 0.7% · -10mm · -1" rim 195/65R15 Safe 0.9% · +10mm · same rim 185/75R14 Safe 1.1% · same width · -1" rim 205/65R15 Safe 1.2% · +20mm · same rim 195/75R14 Safe 1.3% · +10mm · -1" rim 205/55R16 Safe 1.3% · +20mm · +1" rim 195/70R14 Caution 1.8% · +10mm · -1" rim 185/80R14 Caution 1.8% · same width · -1" rim 205/60R16 Caution 1.9% · +20mm · +1" rim

Understanding 185/70R15

The tire size 185/70R15 means the tire has a section width of 185mm, an aspect ratio of 70% (the sidewall height is 70% of the width), and fits a 15-inch rim.

Sidewall Height = 185 x 0.7 = 129.5 mm
Overall Diameter = (129.5 x 2) + (15 x 25.4) = 640.0 mm
Circumference = 640.0 x π = 2010.6 mm

With an aspect ratio of 70%, this is a high-profile tire with a tall sidewall. High-profile tires provide a cushioned ride, better absorption of road imperfections, and greater resistance to sidewall damage — ideal for trucks, SUVs, and off-road use.

Choosing Replacement Tires

When replacing 185/70R15 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.