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Tires

Wheel offset and width calculator

Offset alone does not place a wheel. Width and offset together do.

Wheel and tire position

Lower offset pushes the wheel outward (poke); higher offset pulls it inward (tuck).

suspension sidehub facecurrentnew16 mm outward (poke)
Inner clearance
5.38 in
−0.14 in vs stock
Outer position
2.62 in
+0.64 in vs stock
Scrub radius change
16 mm
noticeable steering feel change

How offset and width combine

Offset is the distance from the wheel's mounting face to its centre line, measured in millimetres. Positive offset means the mounting face is outboard of centre; negative means it is inboard. Width changes how far the wheel extends from that centre, so a wider wheel with the same offset grows equally in both directions.

Working in millimetres from the hub face keeps this simple:

  • Inner position = width × 25.4 ÷ 2 + offset
  • Outer position = width × 25.4 ÷ 2 − offset

If the inner position grows beyond the original, you lose clearance to the strut, control arm or inner fender. If the outer position grows, the wheel sits further out: the look many people want, but it also increases the load on wheel bearings and can put the tire outside the fender line.

Scrub radius and steering feel

Moving the wheel outward moves the tire's contact patch relative to the steering axis, which changes scrub radius. Small changes are unnoticeable. Larger ones show up as heavier or lighter steering, more tramlining on uneven roads, and torque steer in front-wheel-drive cars. If the number here is more than about 15 mm, expect to feel it.

Frequently asked questions

Is lower offset better?
Lower offset pushes the wheel outward for a more aggressive stance, but it increases bearing load and can cause rubbing. It is a trade, not an upgrade.
What does wheel offset mean?
The distance in millimetres from the wheel’s centreline to the face that bolts to the hub. Positive offset puts the mounting face toward the outside, tucking the wheel in; negative offset puts it toward the inside, pushing the wheel out.
Which wheel offset sticks out more?
The lower one. Every millimetre less offset moves the whole wheel a millimetre further out, so going from +45 to +35 puts the outer lip 10 mm closer to the fender.
Is wheel offset the same as backspacing?
No. Backspacing is the distance from the mounting face to the inner edge of the wheel, usually quoted in inches. It depends on both the offset and the wheel width, so two wheels with the same offset but different widths have different backspacing.
Will a wider wheel with the same offset fit?
It grows both inward and outward by half the width increase, so you gain clearance problems on both sides at once.

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