Wheel Offset Types
Understanding how hub mounting position affects wheel stance.
Calculate Offset (ET)
Enter backspacing and overall width to get ET offset.
Offset Result
Calculate Backspacing
Know the ET? Work backwards to find backspacing.
Backspacing Result
Tyre Size Decoder
Enter your tyre size (e.g. 225/45R17) to get real dimensions.
Tyre Dimensions
Speedometer Error
Changed tyre sizes? Find out how far off your speedo reads.
Speedometer Error
| Indicated (km/h) | Actual (km/h) | Difference |
|---|
Spacer → Effective Offset
Adding spacers? See your new effective ET and track change.
Effective Offset After Spacer
Rim ↔ Tyre Width Compatibility
What tyre widths will fit your rim?
Tyre Compatibility
Disclaimer: These are estimates based on common SARS tariff headings. Actual duties depend on the specific HS code, origin country, and SARS valuation. Always confirm with a licensed clearing agent before importing.
SA Import Duty + VAT
Estimate your total landed cost importing JDM parts into South Africa.
● Cached rate from 2026-09-09 23:39 (refreshes every 12h) · You can override the exchange rate above manually.
What this covers: this is Japan Post EMS postage only — the official rate to ship a parcel from a Japanese post office to your door in South Africa. It does not include a proxy service's own fee (Buyee and similar services add their own service + domestic Japan handling charge on top of this), the item's price, or SA import duty/VAT — see the Import Cost calculator for those. Rates are Japan Post's official published Zone 5 table (covers South Africa), current as of 2026-08. DHL isn't included here — DHL pricing varies by shipper/volume (Buyee's own DHL rate reflects their private bulk contract), so there's no single number we can show that would actually be accurate.
EMS Shipping Estimate (Japan → South Africa)
For bulky-but-light items like wheels, volumetric weight is often what actually determines the price — not the scale weight. Enter both; we'll use whichever is higher, exactly how Japan Post itself calculates it.
● Cached rate from 2026-09-09 23:39 · weight rounds up to Japan Post's next pricing bracket, same as a real post office counter. · EMS limits: 150cm max side, 300cm max length+girth, 30kg max weight.
Note: Estimates based on typical SA courier rates (Courier Guy / Fastway / Dawn Wing). Actual quotes may vary. Wheels and heavy freight may incur surcharges — always get a confirmed quote for large shipments.
Domestic SA Shipping Estimator
Estimate door-to-door courier costs within South Africa.
Power
Enter any one value — the rest update instantly.
Torque
Boost Pressure
Weight / Mass
PCD / Bolt Pattern Checker
Check if a wheel's bolt pattern fits your car, or use the JDM car lookup below to find your specs.
JDM Car Fitment Reference
Bolt pattern, centre bore, stock offset range and stud pitch for popular JDM platforms. Click any row to pre-fill the checker above.
| Car | Years | PCD | Centre Bore | Stock ET Range | Stud Thread |
|---|
Enter your new wheel specs and your stock reference (the baseline the fender was designed around). The visualiser draws both to scale and shows how far the tyre edge moves relative to the fender lip.
New Wheel Setup
Stock / Reference Setup
The fender lip is assumed to sit flush with the outer tyre edge of this setup.
Power to Weight
Estimates 0–100 km/h, 0–60 mph, and quarter mile. Results are theoretical — real-world times vary with driver, conditions, and traction.
Search live listings on Yahoo Auctions Japan — filter by diameter, width and price, then jump to Buyee to bid.
GarageLog lets you store your wheel specs, offset notes, service history and mods against each car — free, from the same garage.