Tire to Rim Width Calculator
Every tire is designed for a specific rim width and rated for a range around it. Too narrow a rim bulges the sidewall; too wide stretches it and risks the bead unseating. Check either direction.
Rule of thumb, not the manufacturer's rating.
This approximates the industry (TRA/ETRTO) approved rim-width ranges and matches
published values for common sizes to within half an inch. Every tire model has an
exact approved range on its spec sheet — confirm there before buying, especially
near the edges of the range.
What the result means
- Measuring rim (the tick): the width the tire is designed and rated on. Section width and tread shape are as intended.
- Narrower rim: the sidewall bulges outward — more rim protection and a softer ride, slower steering. Off-roaders often run a half-inch narrow. Below the range the bead may not seat correctly.
- Wider rim: the sidewall pulls inward ("stretch") — crisper steering, exposed rim lip. Beyond the range the bead can unseat under load or on a curb strike.
- Effective width: tire section width changes about 5 mm per half-inch of rim width. Use this number in the fitment calculator for a tighter clearance estimate.
Common sizes
| Tire | Measuring rim | Acceptable rims |
|---|---|---|
| 205/55R16 | 6.5" | 5.5" – 7.5" |
| 225/45R17 | 7.5" | 7" – 8.5" |
| 245/45R17 | 8" | 7.5" – 9" |
| 235/65R17 | 7" | 6" – 8" |
| 265/70R17 | 8" | 7" – 9" |
| 275/55R20 | 8.5" | 7.5" – 9.5" |
| 285/70R17 | 8.5" | 7.5" – 9.5" |
| 275/40R20 | 9.5" | 9" – 10.5" |
| 33x12.50R17 | 10" | 9" – 11" |
| 35x12.50R17 | 10" | 9" – 11" |