Vehicle Trim Tire Size Lookup
Find the size for your trim and wheels. Use the calculator below. Results update as you type.
How the Vehicle Trim Tire Size Lookup Works
This lookup works by listing the factory wheel and tire options for each trim level of a model and showing how their diameters compare. Higher trims often get larger wheels with lower-profile tires at the same overall diameter.
- Select the model and year.
- Select the trim, for example the 19 in wheel trim.
- Read the size: 245/45R19 at 27.68 in.
- Compare with the other trims' sizes in the same table.
The Formula
The formula compares each trim size with the model's common diameter: Change (%) = (D_trim − D_ref) ÷ D_ref × 100.
D_trim = (Rim × 25.4) + 2 × (Width × Aspect Ratio ÷ 100) Change (%) = (D_trim − D_ref) ÷ D_ref × 100Worked example: a 245/55R17 base trim (27.61 in) and a 245/45R19 upper trim (27.68 in) differ by 0.25%. Wheels from either trim swap without speedometer changes, if brake clearance allows.
Conversion Table
The conversion table shows 6 wheel diameters from 16 in to 21 in sized to one 27.6 in (701 mm) diameter. All 6 sizes sit within ±0.45% of the 27.6 in target.
The sidewall column shows the trade-off: 5.79 in on the 16 in wheel and 3.24 in on the 21 in wheel.
| Trim Wheel | Matching Size | Diameter (in) | vs 27.6 in | Sidewall (in) |
|---|---|---|---|---|
| 16 in trim | 245/60R16 | 27.57 | -0.09% | 5.79 |
| 17 in trim | 245/55R17 | 27.61 | +0.04% | 5.31 |
| 18 in trim | 245/50R18 | 27.65 | +0.17% | 4.82 |
| 19 in trim | 245/45R19 | 27.68 | +0.29% | 4.34 |
| 20 in trim | 215/45R20 | 27.62 | +0.07% | 3.81 |
| 21 in trim | 235/35R21 | 27.48 | -0.45% | 3.24 |
Example of how one model can carry 6 different factory sizes that roll at nearly the same diameter.
What Is the Vehicle Trim Tire Size Lookup?
The Vehicle Trim Tire Size Lookup is a tool that shows which tire sizes came on each trim level of a vehicle. One model can carry 4 to 6 different factory sizes across trims.
Trim sizes matter when buying a used car, swapping wheels between trims or ordering winter wheels. The lookup shows all options in one view.
Common Uses
This lookup has 4 uses: trim wheel swaps, used-car checks, winter planning and upgrade planning.
- Swap trim wheels: Fit wheels from a higher or lower trim.
- Check used cars: Confirm the right size for the trim.
- Plan winter sets: Use the smallest trim wheel for winter.
- Plan upgrades: Move to a higher trim's wheel size.