Compare wheel diameter, width, offset, backspacing, poke, inner clearance, bolt pattern spacing, and wheel fitment changes. Use this converter when comparing wheels like 17x8 +35, 18x9 +25, or other aftermarket wheel sizes.
Width in mm:
wheel width inches × 25.4
Backspacing:
(wheel width ÷ 2) + offset
Inner position:
half width + offset
Outer position:
half width - offset
Wheel size conversions are useful for aftermarket wheels, OEM wheel comparisons, track width changes, offset changes, backspacing checks, stance planning, brake clearance, suspension clearance, and wheel fitment planning.
Use this converter as a planning tool, then confirm fitment with a wheel shop, vehicle manufacturer, or trusted fitment guide.
Your result compares the original wheel with the new wheel. It shows changes in outer poke, inner clearance, backspacing, wheel width, diameter, offset, and bolt pattern.
Wheel changes can affect tire clearance, fender clearance, suspension clearance, brake clearance, scrub radius, steering feel, ride comfort, handling, and bearing load.
It means the wheel is 18 inches in diameter, 9 inches wide, and has a +25 mm offset.
Wheel offset is the distance from the wheel centerline to the mounting surface. Positive offset moves the wheel inward, while lower offset usually pushes it outward.
Backspacing is the distance from the wheel mounting surface to the inner edge of the wheel.
Often, yes. A wider wheel can increase outer poke, but the final position also depends on offset.
No. It estimates wheel position changes. You still need to check tire size, suspension clearance, brake clearance, fender clearance, center bore, and bolt pattern.