Poke, flush,or tucked.

Offset, backspacing, and width

Offset is the distance in millimetres from the wheel's mounting face to its centerline. Positive offset puts the mounting face outboard of centre, which pulls the wheel inward under the fender. Negative offset puts it inboard, which pushes the wheel outward toward — and past — the fender. A wheel stamped ET35 has 35 mm of positive offset; one stamped ET−18 has 18 mm of negative offset.

Backspacing measures the same geometry from the other direction: the distance from the mounting face to the inner lip, in inches. Truck and off-road catalogues quote backspacing; car and European catalogues quote offset. They describe the same thing, and the tool shows backspacing so you can cross-reference either spec sheet.

Width is the trap. Adding an inch of width at the same offset does not push the wheel out an inch — it pushes it out half an inch and in half an inch, because the mounting face stays put and both lips move. That inner half-inch is what finds your strut, your upper control arm, or your brake caliper, and it is the reason people who only think about poke end up with rub they did not expect.

Reading the verdict

The tool compares your setup against a common 8.5″ +35 factory wheel, which is a reasonable stand-in for a lot of modern trucks and crossovers. Four ranges cover most outcomes:

• Tucked — the wheel sits inside the fender line. Quiet, no rock chips down the side, easiest on bearings. Too much and the inner edge runs out of room.
• Flush — the outer lip lines up with the fender. What most people mean by "clean." Fits without drama on most vehicles.
• Slight poke — the lip sits proudly past the fender. Aggressive without being loud; expect some road spray down the sides.
• Aggressive poke — well past the fender. Real stance, real consequences: rub at full lock, rock chips along the doors, and in some places a fender-coverage question.

What the tool cannot know

This is a two-dimensional front view of a generic fender. It does not know your vehicle's fender liner, brake caliper diameter, strut body, upper control arm geometry, or suspension travel. Every specification is measured static, and clearances shrink under load: hit a bump at full steering lock and a setup with a quarter inch of static clearance can touch.

That gap between arithmetic and reality is why we verify fitment against builds we have actually done before anything is ordered, and why the fitment guarantee exists — if a setup we spec'd rubs or will not clear, we swap it and cover the freight. Thefitment finder on the wheels and tires page shows three verified setups per vehicle, which is the better starting point if you have not settled on a size yet.

Hardware, because it matters

Correct seat type (conical, ball, or flat with washers), correct thread pitch, and hub-centric rings on any wheel whose centre bore is larger than your hub. Rings are not optional cosmetics — without them the studs carry the vehicle's weight instead of the hub, which is how you get a vibration nobody can balance out. Every install here is torqued to spec and re-checked free at 50 miles.

Once you have a width and offset in mind, run the size through thetire size calculator to check overall diameter, then see package pricing on the wheels and tires page.