Wheel Offset Visualizer
Draw how a new offset moves the wheel. Use the calculator below. Results update as you type.
Offset = Distance from Wheel Centerline to Hub Mounting FaceHow the Wheel Offset Visualizer Works
This visualizer works by drawing a wheel in cross-section relative to the hub mounting face and moving it as you change width and offset. It shows the inner and outer edges in millimeters and inches.
- Enter the wheel width, for example 8.5 in (216 mm).
- Enter the ET value, for example ET40.
- View the wheel drawn against the hub face.
- Read the inner (147.9 mm) and outer (67.9 mm) bead seat positions.
The Formula
The formula is Inner = Half Width + Offset and Outer = Half Width − Offset.
Offset = Distance from Wheel Centerline to Hub Mounting Face Inner (mm) = W × 12.7 + ET Outer (mm) = W × 12.7 − ET Backspacing (in) = Inner ÷ 25.4 + 0.5Worked example: an 8.5 in ET20 wheel has its inner bead seat 127.9 mm and its outer bead seat 87.9 mm from the hub face.
Conversion Table
The conversion table shows where an 8.5 in (216 mm) wheel sits at 6 offsets from ET20 to ET50. Each row lists inner and outer bead seat positions in mm and backspacing and frontspacing in inches.
Every 10 mm offset step moves both edges by 10 mm in the same direction.
| Offset | Inner Bead Seat (mm) | Outer Bead Seat (mm) | Backspacing (in) | Frontspacing (in) |
|---|---|---|---|---|
| ET20 | 127.9 | 87.9 | 5.54 | 3.96 |
| ET30 | 137.9 | 77.9 | 5.93 | 3.57 |
| ET35 | 142.9 | 72.9 | 6.13 | 3.37 |
| ET40 | 147.9 | 67.9 | 6.32 | 3.18 |
| ET45 | 152.9 | 62.9 | 6.52 | 2.98 |
| ET50 | 157.9 | 57.9 | 6.72 | 2.78 |
What Is the Wheel Offset Visualizer?
The Wheel Offset Visualizer is a tool that illustrates static wheel position changes from offset and width. It draws what the offset numbers mean.
Offset is the least intuitive wheel number. A drawing makes clear that positive offset pulls the wheel in and negative offset pushes it out.
Common Uses
This visualizer has 4 uses: offset learning, stance previews, catalog comparison and customer explanations.
- Learn offset: See what ET values mean.
- Preview stance: See how far the wheel moves.
- Compare catalog wheels: Draw 2 offsets together.
- Explain to customers: Show poke and inset visually.