Rim diameter guide

How do you match tire size to rim diameter?

The last number in a tire size (R17 = 17 inches) must match the rim diameter exactly. The section width also affects which rim width is recommended — a wider tire needs a wider rim for correct bead seating.

FAQ

How do you match tire size to rim diameter?
The last number in a tire size (R17 = 17 inches) must match the rim diameter exactly. The section width also affects which rim width is recommended — a wider tire needs a wider rim for correct bead seating.
What should I verify before using this information?
Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.

Seasonal check

Planning a long summer drive?

Use the budget and running-cost tools before a trip, especially if the current tyres are worn or the replacement size changes diameter.

Estimate tyre budget
Last reviewed: 2026-06-28
What changed
  • Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.