Toe and Camber Calculator

Why the same toe has three different numbers

Toe is the angle each front wheel makes with the centreline of the car, and it gets written down three different ways depending on who is writing it. Per wheel or total is the first split: total toe is the algebraic sum of the two wheels, so a car with each wheel set to 1 degree of toe-in has 2 degrees of total toe, and a spec sheet that says 2 mm without saying which one it means is ambiguous by half. Distance or angle is the second split, and it is the one that quietly ruins numbers. An angle is a property of the wheel's direction and nothing else. A distance is that angle multiplied by the diameter it was measured across, so it changes the moment you measure somewhere else.

The default on this page is the arithmetic worth remembering. One degree of toe-in on a 15 inch rim, which is 381 mm across, is 6.65 mm measured front to back on the rim lip. Move the tape out to the tire of a 205/60R15, 627 mm across, and the same one degree measures 10.94 mm. Nothing about the car changed; the ruler moved. That is why manufacturers publish alignment specs in degrees or in degrees and minutes, and why a millimetre figure copied from a forum post is only usable if the post also said what it was measured across. If you need the diameter of a tire size you do not have in front of you, the tire size calculator works it out from the size code and this page will take the same number.

Making a string measurement that means something

A string box, or two strings pulled taut down the sides of the car at hub height, gives readings good enough to work with if the setup is square. The strings have to be parallel to each other, and each one has to sit the same distance from the centreline of the car, not from the bodywork. Then the reading that matters is the distance from string to rim lip at the front of the wheel and at the back of the wheel, on the same wheel, and the difference between those two is what this page calls the distance per wheel. Front smaller than rear is toe-in.

Two details decide whether the result is worth anything. Measure at the rim lip rather than the tire wall where you can, because a sidewall bulges under load and a bulge in the middle of the tape is indistinguishable from toe. Then measure the same wheel twice with the car rolled forward half a turn and averaged, because a rim with a flat spot or a dented lip puts its runout straight into the reading, and a bent lip is far more common than people expect on a car that has met a kerb. The error table above prices this out: half a millimetre of misread tape on a 381 mm rim is 0.075 degrees per wheel, and the same error on both wheels is 0.15 degrees of total toe, which is a real fraction of a typical spec.

Camber from a level and a ruler

Camber is the tilt of the wheel seen from the front, and it comes out of exactly the same trigonometry: the arc tangent of how far the top of the wheel sits from the bottom, over the vertical distance between the two points you measured. Negative camber is the top leaning in toward the car. Hold a straight edge or a spirit level against the wheel face, measure the gap at the top and the gap at the bottom, subtract, and the difference over the height between those two points is the angle. The height matters as much as the offset does, which is the part people leave out. Two millimetres over a 300 mm gauge is 0.38 degrees, but two millimetres over a 600 mm gauge is 0.19 degrees, and neither number means anything on its own.

Both measurements need level ground, or at least ground that is equally unlevel on both sides, since the car sits on the surface it is parked on and reads the crown of a road as camber. A digital camber gauge that clamps to the wheel and reads degrees needs none of this conversion, which is what you are paying for. If you are moving weight around the car while you set it up, the corner weight calculator handles the scale side, and remember that camber and toe both move with ride height, so an alignment is only true at the height it was set at.

What this tool will not do

It will not tell you what to run. There is no recommended toe or camber figure anywhere on this page, because the right number depends on the tire, the track, the surface, the driver and how much tire temperature you are willing to trade for turn-in, and a calculator that offered one would be inventing confidence it has not earned. It also does not model anything the wheel does while moving: bump steer, camber gain through travel, compliance under load and the difference between static and rolling toe are all real and none of them are here. Nor does it convert caster, kingpin inclination or thrust angle, and it assumes both sides of the axle carry the same setting, which is exactly what you should check rather than assume.