Custom Diameter Tolerance Filter
Set your own limit for how much the height can change. Use the calculator below. Results update as you type.
Overall Diameter = (Rim Diameter × 25.4) + 2 × (Width × Aspect Ratio / 100)How the Custom Diameter Tolerance Filter Works
This tool works by building a diameter window around a baseline size and keeping only candidates inside it. You choose the tolerance: ±1%, ±2%, ±3% or any custom value.
- Enter the baseline size, for example 265/70R17 (31.61 in).
- Choose a tolerance, for example ±2%.
- Read the window: 30.97 in to 32.24 in.
- Read the filtered list of sizes inside the window.
The Formula
The formula is Window = Baseline Diameter × (1 ± Tolerance ÷ 100).
D_min = D_base × (1 − Tol ÷ 100) D_max = D_base × (1 + Tol ÷ 100) Overall Diameter = (Rim Diameter × 25.4) + 2 × (Width × Aspect Ratio ÷ 100)Worked example: a 225/65R17 is 28.52 in. At ±1%, the window is 28.23 in to 28.80 in. A 235/60R17 at 28.10 in falls outside.
Conversion Table
The conversion table shows the allowed diameter window at ±1%, ±2% and ±3% for 6 baseline sizes. Windows widen from about 0.6 in (±1%) to about 1.9 in (±3%) on a 31.6 in tire.
Use ±1% for AWD vehicles with strict tire-matching rules, ±2% for daily drivers, and ±3% as the outer limit for most passenger vehicles.
| Baseline | Diameter (in) | ±1% Window | ±2% Window | ±3% Window |
|---|---|---|---|---|
| 205/55R16 | 24.88 | 24.63 – 25.13 | 24.38 – 25.38 | 24.13 – 25.62 |
| 225/45R17 | 24.97 | 24.72 – 25.22 | 24.47 – 25.47 | 24.22 – 25.72 |
| 225/65R17 | 28.52 | 28.23 – 28.80 | 27.95 – 29.09 | 27.66 – 29.37 |
| 245/60R18 | 29.57 | 29.28 – 29.87 | 28.98 – 30.17 | 28.69 – 30.46 |
| 265/70R17 | 31.61 | 31.29 – 31.92 | 30.97 – 32.24 | 30.66 – 32.55 |
| 275/65R20 | 34.07 | 33.73 – 34.42 | 33.39 – 34.76 | 33.05 – 35.10 |
What Is the Custom Diameter Tolerance Filter?
The Custom Diameter Tolerance Filter is a tool that limits tire choices to a diameter window you set. Different vehicles and uses need different tolerances.
The ±3% window is a shop rule of thumb. Some AWD makers set tighter limits, and some owners accept wider gaps for lift builds. The filter lets you set the rule instead of using a fixed one.
Common Uses
This tool has 4 uses: AWD limits, maker rules, lift builds and quick screening.
- Apply AWD limits: Filter to ±1% for strict systems.
- Follow maker rules: Enter the tolerance in the owner's manual.
- Screen lift builds: Widen the window for planned upsizes.
- Screen quickly: Cut a long list to sizes that fit the rule.