Same-Rim Alternative Size Finder
Find other sizes that fit the rim you have. Use the calculator below. Results update as you type.
How the Same-Rim Alternative Size Finder Works
This finder works by locking the rim diameter and listing every width and aspect ratio that lands near the target diameter. It suits owners who want to keep their current wheels.
- Enter the rim diameter, for example 17 in.
- Enter the target diameter, for example 28.5 in (724 mm).
- Read the ranked list: 225/65R17 at +0.06%, 265/55R17 at −0.08%.
- Check each result's width against your rim's approved range.
The Formula
The formula holds Rim constant and solves the overall diameter for each width and aspect pair.
D = (Rim × 25.4) + 2 × (Width × Aspect Ratio ÷ 100) Change (%) = (D − D_target) ÷ D_target × 100Worked example on a 17 in rim: 245/60R17 gives 431.8 + 294 = 725.8 mm (28.57 in), which is +0.26% from a 28.5 in target.
Conversion Table
The conversion table lists 12 sizes on a 17 in rim near a 28.5 in (724 mm) target. Every gap stays within ±1.85%.
The width column shows the trade-off. You can stay near 28.5 in with a 205 mm tire (8.07 in) or a 295 mm tire (11.61 in), but each needs a different rim width.
| 17 in Size | Diameter (in) | vs 28.5 in | Width (in) |
|---|---|---|---|
| 225/65R17 | 28.52 | +0.06% | 8.86 |
| 265/55R17 | 28.48 | -0.08% | 10.43 |
| 245/60R17 | 28.57 | +0.26% | 9.65 |
| 295/50R17 | 28.61 | +0.40% | 11.61 |
| 205/70R17 | 28.30 | -0.70% | 8.07 |
| 285/50R17 | 28.22 | -0.98% | 11.22 |
| 215/70R17 | 28.85 | +1.23% | 8.46 |
| 235/60R17 | 28.10 | -1.40% | 9.25 |
| 275/55R17 | 28.91 | +1.44% | 10.83 |
| 255/55R17 | 28.04 | -1.60% | 10.04 |
| 215/65R17 | 28.00 | -1.74% | 8.46 |
| 235/65R17 | 29.03 | +1.85% | 9.25 |
What Is the Same-Rim Alternative Size Finder?
The Same-Rim Alternative Size Finder is a tool that lists alternative tire sizes that fit your existing wheel diameter and stay close to a target height. Changing tires without changing wheels is the cheapest size change.
The finder answers questions such as "Can I go wider on my 17 in wheels?" and "Which sizes fit my rims if my size is out of stock?"
Common Uses
This finder has 4 uses: going wider, going narrower for winter, finding stock and keeping wheels.
- Go wider: Find wider sizes that keep the current rim and height.
- Go narrower for winter: Find a narrow size that cuts through snow.
- Find in-stock options: Search alternatives when your size is scarce.
- Keep your wheels: Avoid buying new wheels for a size change.