Wheel Fitment Calculator
Real fitment math, instantly. Check if new wheels will clear your fenders and suspension, convert offset to backspacing, and compare tire sizes — all without leaving the page.
Optional — Prefill from your vehicle
Current / Stock Setup
New / Candidate Setup
Enter both setups above to see the fitment comparison.
Guide
How to use this calculator
Will it fit? tab
Enter your current wheel width and offset (plus an optional tire spec like 245/45R19). Then enter your new setup. The calculator shows how much the outer edge moves toward or away from your fender lip, how much inner clearance changes, and — if you add tire sizes — speedometer error.
Use the vehicle picker to prefill the current side from OEM specs and see the recommended offset range for your exact make and model.
Offset ↔ Backspacing tab
Some older catalogs and off-road shops list wheel fitment in backspacing (inches from inner lip to mounting face) instead of offset (mm). Enter either value plus wheel width and get the other instantly. The conversion uses the industry-standard 0.5″ inner barrel lip allowance.
Not sure what offset means or how it differs from backspacing? The guides explain both in plain English.
Tire size tab
Enter a tire spec (e.g. 245/45R19) to get overall diameter, sidewall height, and circumference. Add a second size to compare — the tool calculates the diameter percentage difference and the expected speedometer error.
Staying within ±3% of factory diameter keeps your odometer and ABS within acceptable tolerance for most vehicles.
Guide
What is wheel offset?
Positive vs. negative, how it moves your wheel in and out, and what range is safe for your car.
Guide
Wheel backspacing explained
How backspacing is measured, how it relates to offset, and when you will see it listed instead.
Reference
Bolt pattern reference
Every common bolt pattern with vehicle compatibility — look up by PCD or by make and model.
FAQ
Common questions
- Will these wheels fit my car?
- To know if a wheel fits, you need to match four things: bolt pattern (number of lugs and PCD), hub bore (center hole diameter), offset (how far the mounting face is from wheel centerline), and overall width. Enter your current and new setup in the calculator above — it will show you exactly how much the outer edge and inner clearance change, so you can judge fender and suspension contact before you buy.
- What does wheel offset do to fitment?
- Offset is the distance in millimetres between the wheel's mounting face and its centerline. A higher (more positive) offset tucks the wheel inboard — more clearance at the fender lip but less at the suspension. A lower or negative offset pushes the wheel outward for a more aggressive stance. Changing offset shifts both the inner and outer edges simultaneously; the calculator shows both deltas so you can evaluate each separately.
- How do I know if a tire size will fit?
- The key metric is overall diameter. A tire that is more than about 3% larger or smaller than the original will affect your speedometer, clearance, and gear ratios noticeably. Use the Tire Size tab above to compare two sizes — it shows overall diameter, sidewall height, and estimated speedometer error so you can pick a size that stays close to your factory rolling circumference.
- What is a safe offset range?
- For most passenger cars and crossovers, staying within ±10mm of the OEM offset keeps you comfortably clear of fenders and suspension components. Going 15–20mm lower (more outboard) typically requires a visual fender check; beyond 25mm you may need a clearance test drive over full suspension travel. The vehicle picker in the calculator shows the recommended offset range for popular makes and models based on OEM specs.
Ready to shop?
See wheels that actually fit your car
Every wheel on AlloyHaus is checked against your bolt pattern, hub bore, and offset range. No guesswork required.