Estimate tire tread life and replacement timing by tread depth.
Depth lost from new is divided by the usable depth range and scaled against the tire's expected mileage. Tires below 4/32 inch lose their grip in the wet, so depth is the reliable way to decide when to replace them.
Tire Life
Remaining = tire life x (current - minimum) / (new - minimum)
Remaining = tire life x (current - minimum) / (new - minimum) Depth lost from new is divided by the usable depth range and scaled against the tire's expected mileage.
Tires below 4/32 inch lose their grip in the wet, so depth is the reliable way to decide when to replace them.
This calculator takes 4 inputs: New tread depth, Current tread depth, Minimum depth, Typical tire life. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.