⭐ Wheel Offset, Backspace & Frontspace Explained
This tool helps you accurately understand and compare wheel fitment when upgrading or changing wheel sizes. Whether you're moving to wider wheels, trying to clear suspension components, fitting drag wheels, or fine-tuning stance, the three essential measurements you must understand are offset, backspace, and frontspace.
What This Calculator Does
Enter your wheel width and any one of the three measurements — offset, backspace, or frontspace. The calculator instantly determines the other two.
This allows you to:
- Convert offset to backspace and frontspace
- Convert backspace to offset and frontspace
- Convert frontspace to offset and backspace
- Compare multiple wheel setups side-by-side
- Understand how a change in wheel width affects fitment
- Predict inner and outer movement before purchasing wheels
Why Backspace & Frontspace Matter
Offset alone doesn’t tell you exactly where the wheel will sit.
Backspace and frontspace directly measure:
- Backspace: distance from the mounting pad to the inner lip
- Frontspace: distance from the mounting pad to the outer lip
These determine:
- Inner clearance to suspension and chassis
- Outer clearance to the fender or quarter panel
- Whether a wheel pokes out or tucks in
- Brake and coilover clearance
Real-World Use Cases
This fitment tool is useful when you are:
- Upsizing to wider wheels
- Switching from OEM wheels to aftermarket
- Moving from 17”/18” to 19”/20”
- Planning drag-race fitment
- Trying to clear big brakes
- Comparing multiple wheel offsets
- Ensuring inner fender clearance on lowered vehicles
How Wheel Width Is Measured
Wheel width is measured from bead seat to bead seat, not the total physical width.
A “9.5-inch” wheel is actually about 10.5 inches wide overall because each lip adds roughly half an inch.
This calculator automatically accounts for the extra inch so your results reflect real-world wheel fitment.
Use the Calculator Above
Use the tool above to:
- Plan your next wheel purchase
- Compare different offsets
- See how much a new wheel will poke or tuck
- Ensure clearance before ordering expensive wheels
It’s a fast and accurate way to dial in the perfect wheel setup for your vehicle.
Do you have an idea on how to make this calculator even better? Share your idea below.
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