Multiple Tire Size Comparator
Compare three or more sizes at once. Use the calculator below. Results update as you type.
How the Multiple Tire Size Comparator Works
This comparator works by measuring several candidate sizes against one baseline and ranking them by diameter difference. It replaces running 5 or 10 separate 2-tire comparisons.
- Enter the baseline size, for example 225/65R17 (28.52 in).
- Add candidate sizes, one per line.
- Read each candidate's diameter, change in percent and width change in mm.
- Filter the list to sizes marked Yes in the ±3% column.
The Formula
The formula applies Change (%) = (Candidate Diameter − Baseline Diameter) ÷ Baseline Diameter × 100 to every candidate.
Change_i (%) = (D_i − D_base) ÷ D_base × 100 Width Change_i (mm) = W_i − W_base Pass_i = |Change_i| ≤ 3%Worked example: 245/60R18 has D = 29.57 in. Against a 28.52 in baseline, the change is +3.71%, so the size fails the ±3% filter.
Conversion Table
The conversion table compares 9 candidates with a 225/65R17 baseline. Seven candidates pass the ±3% check and 2 fail.
The 225/60R18 and 225/70R16 are the closest matches at +0.40% and −0.40%. The 245/50R20 is the furthest at +3.96%.
| Candidate | Diameter (in) | Diameter Change | Width Change (mm) | Within ±3% |
|---|---|---|---|---|
| 215/70R17 | 28.85 | +1.17% | -10 | Yes |
| 225/60R18 | 28.63 | +0.40% | 0 | Yes |
| 235/55R18 | 28.18 | -1.19% | +10 | Yes |
| 235/60R17 | 28.10 | -1.45% | +10 | Yes |
| 235/65R17 | 29.03 | +1.79% | +10 | Yes |
| 245/60R18 | 29.57 | +3.71% | +20 | No |
| 235/55R19 | 29.18 | +2.32% | +10 | Yes |
| 245/50R20 | 29.65 | +3.96% | +20 | No |
| 225/70R16 | 28.40 | -0.40% | 0 | Yes |
What Is the Multiple Tire Size Comparator?
The Multiple Tire Size Comparator is a tool that ranks many tire sizes against a single baseline in one table. It suits buyers with a short list from a tire shop, a set of trim-level options or a used-wheel listing.
The comparator keeps the baseline fixed, so every row uses the same reference. That makes the ranking fair: the best match is the size with the smallest absolute change.
Common Uses
This comparator has 4 uses: shortlist ranking, used-wheel checks, cross-trim swaps and stock substitution.
- Rank shortlists: Sort a dealer's options by closeness to the factory size.
- Check used wheels: Test which sizes fit a different wheel diameter.
- Swap across trims: Compare wheels from a higher or lower trim.
- Substitute stock: Pick the nearest in-stock size during shortages.