How to Read Your Tire Size (185/65R15 Explained)
Published 26 May 2026 · Atika Auto Parts
Every tire has a code stamped on the sidewall like 185/65R15. It looks confusing, but each part has a clear meaning — and getting it right keeps your speedometer accurate and your car safe.
Breaking down 185/65R15
- 185 — the section width in millimetres (how wide the tire is).
- 65 — the aspect ratio: the sidewall height as a percentage of the width.
- R — radial construction (standard on modern tires).
- 15 — the wheel rim diameter in inches.
The load and speed rating
After the size you will often see something like 88H. The number (88) is the load index — how much weight the tire can carry — and the letter (H) is the speed rating. Always match or exceed your vehicle’s recommended ratings, which you can find on the sticker inside the driver’s door.
Where to find your size
Check the sidewall of your current tires, or the placard inside the driver door jamb. Once you know your size, you can shop it directly — for example, browse all 185/65R15 tires on our site.
Still unsure? Bring your vehicle to Atika Auto Parts at 11 Automatic Road, Brampton, or call +1 (204) 962-8513 and we will confirm the correct size and show you brand new options in stock.
