Toe Explained: Toe-In, Toe-Out, and Converting Millimeters to Degrees
Toe is the direction the wheels point when viewed from above. Toe-in means the fronts of the two wheels on an axle are closer together than the rears; toe-out is the opposite. The amounts are tiny — usually a fraction of a degree — but toe has more influence on tire life and on how a car responds to the first few degrees of steering than any other alignment setting.
What each direction does
| Setting | Effect on the car | Cost |
|---|---|---|
| Front toe-in | Calmer on-center feel, stable in a straight line | Slower turn-in |
| Front toe-out | Sharper, more eager turn-in | Wanders and follows ruts; nervous at speed |
| Rear toe-in | Stable under power and when lifting off | More rear tire wear; can add understeer |
| Rear toe-out | Rear rotates readily | Unstable; rarely used outside special cases |
Most road cars are specified with a little toe-in at both ends. Rubber suspension bushes deflect under load, and a small static toe-in keeps the wheels from being pushed into toe-out when the car is braking or coasting.
Total toe and per-wheel toe
Alignment sheets quote toe two ways. Per-wheel toe is each wheel's angle relative to the car's centerline. Total toe is the two added together. A car with 0.10° in on each side has 0.20° total. On the rear axle the per-wheel numbers matter separately: unequal rear toe points the axle off to one side (a thrust angle), and the car "crabs" with the steering wheel off-center.
Converting millimeters, inches and degrees
Toe is quoted as an angle or as a distance — the difference between the front and rear of the rims. A distance only means something together with the diameter it was measured across, which is why the same car can have a spec in millimeters that looks different from one workshop to another.
| Total toe | Across a 17" rim (432mm) | Across a 19" rim (483mm) |
|---|---|---|
| 0.10° | 0.8mm | 0.8mm |
| 0.20° | 1.5mm | 1.7mm |
| 0.50° | 3.8mm | 4.2mm |
Measuring across the tire tread instead of the rim gives a bigger number again for the same angle. When comparing a setting against a specification, check which diameter the specification assumes, or work in degrees.
Why toe wears tires
A toed wheel is not rolling in the direction the car is travelling, so the tread is scrubbed sideways continuously. At 0.5° of toe on a wheel, the tire is being dragged sideways roughly 9 meters for every kilometer driven. The wear shows as feathering — tread blocks worn sharp on one edge — and it is concentrated on the inner shoulder when combined with negative camber.
Toe moves when anything else does
- Ride height — lowering changes the tie rod angle and usually changes toe. Always re-align after a height change.
- Camber and caster adjustments — both move the knuckle relative to the tie rod, so toe is set last.
- Suspension travel — toe change with bump and droop is bump steer, a separate problem from the static setting.
- Wheels and tires — a different wheel width or offset does not change toe angle, but a larger diameter makes the same angle a larger distance.