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Tire Replacement Calculator
Work through the factors that decide tire replacement — tread depth, tire age, visible damage and uneven wear — and get plain guidance on whether to keep monitoring or replace.
Tire replacement triage
Answer a few questions for a general indication of whether a tire needs attention. This is triage only — it does not certify safety.
Measure in the shallowest groove.
Indication
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- Tread (32nds)
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- Tread (mm)
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- Age
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For any safety decision, follow the vehicle and tire manufacturer's specifications and have a qualified technician inspect the tire.
How to use this tool
Answer each question as accurately as you can. The tool weighs tread depth, age, damage and wear pattern to give general guidance, which you should confirm with a qualified professional.
- Enter your approximate tread depth, measured in the main grooves, in thirty-seconds of an inch or millimetres.
- Enter the tire's age by reading the four-digit DOT date code on the sidewall.
- Note any visible damage such as cracks, bulges or exposed cords, and note whether wear is even across the tread.
A tire with 3/32 inch of tread and a 2017 date code, showing even wear and no damage, would be flagged for replacement on both tread and age grounds — two independent reasons to replace.
What the results mean
Tread depth governs grip in wet and snowy conditions; 2/32 inch is the legal minimum in most US states but performance degrades well before that, and many manufacturers recommend replacement at 4/32 inch for wet safety. Age matters because rubber hardens and can fail even with tread remaining, which is why many manufacturers advise replacement after about six years and inspection after five. Damage such as bulges or exposed cords is an immediate safety concern.
How it is calculated
The tool applies commonly published thresholds: a minimum legal tread of 2/32 inch, a wet-safety warning near 4/32 inch, an age inspection point around five years and a replacement recommendation around six years, plus automatic flags for structural damage.
Important limitations
This is guidance, not an inspection. Tread depth should be measured in several places because wear is rarely even, and only a professional can safely judge internal or sidewall damage. Your tire and vehicle manufacturer's guidance, and your state's legal minimum, always take precedence.