Tread Depth Calculator & UTQG Treadwear Rating Explainer
Typical new tires ≈ 10/32" • Replace for wet safety at 4/32" • Legal minimum often 2/32"
QUICK EXAMPLE
A typical new all‑season tire starts with about 10/32" of tread depth. If it now measures 6/32", you have used half of the usable tread (6/32" − 2/32" out of 10/32" − 2/32"), leaving roughly 50% of usable life. At 4/32", only about 25% usable tread remains and most safety experts recommend replacement for wet‑weather driving. At 2/32", tread wear bars are flush with the surface — you are at 0% usable life and at, or below, the legal minimum in many regions.
Common ratings:
Treadwear Rating
400
vs Reference
4.0×
longevity
Est. Mileage Low
72,000
miles
Est. Mileage High
100,800
miles
What This Means
Good everyday durability. Most popular range for family vehicles.
Mileage estimates assume normal driving conditions. Real-world wear varies significantly with driving style, alignment, inflation, and road surfaces. UTQG testing is comparative, not an absolute guarantee.
UTQG Treadwear Reference
| Rating | Category | Est. Mileage |
|---|---|---|
| 60 | Racing / Track | < 5,000 mi |
| 100 | UTQG Reference | ~15,000–18,000 mi |
| 200 | High Performance | ~25,000–35,000 mi |
| 300 | Performance All-Season | ~40,000–55,000 mi |
| 400 | Standard All-Season | ~55,000–70,000 mi |
| 500 | Touring | ~70,000–85,000 mi |
| 600 | Grand Touring | ~80,000–100,000 mi |
| 800 | Maximum Longevity | ~100,000+ mi |
AI Insight
Powered by AIGet a plain-English explanation of your results — what they mean for your vehicle and driving experience.
Tire Tread Depth Life Guide
| Tread Depth | % Usable Remaining* | Status | Recommendation |
|---|---|---|---|
| 10/32" | 100% | New / Excellent | Full tread depth; optimal performance |
| 7–8/32" | 75–87% | Very Good | Safe for most conditions; monitor wear |
| 6/32" | 50% | Fair | Still acceptable; start planning replacement |
| 4/32" | 25% | Replace Soon | Wet traction reduced; replace for rainy climates |
| 3/32" | 12% | Danger Zone | High hydroplaning risk; replace as soon as possible |
| 2/32" | 0% | Legal Minimum | Legally worn out in many areas; replace immediately |
*Usable tread percentage assumes a typical new depth of about 10/32" and 2/32" as the minimum legal depth. Different categories (performance, winter, off‑road) may start with more or less tread, so percentages are approximate.
How to Use This Calculator
- Enter the Original (New) Tread Depth of your tire (most passenger tires start around 9/32" to 11/32"; winter and truck tires may be deeper).
- Enter the Current / Remaining Tread Depth measured with a tread gauge (or using the penny/quarter tests converted to 32nds).
- Click 'Calculate Remaining Life'.
- Review the remaining usable tread percentage, status band, and replacement recommendation.
Formula & Tread Life Guide
About Tread Depth & UTQG Treadwear Ratings
Tread Depth Guidelines by Condition
Most new passenger all‑season tires start around 10/32" to 11/32" of tread depth, performance tires slightly shallower (about 8/32" to 10/32"), and winter or off‑road tires deeper (11/32" to 18/32" or more). Above about 6/32", you generally have good traction in most conditions. Around 4/32", wet braking distances increase and hydroplaning resistance drops, which is why many experts recommend replacing tires at or before that point for rainy climates. At 2/32", tread wear indicators are flush with the surface and the tire is legally worn out in many jurisdictions.
Safety vs Legal Minimum
The legal minimum tread depth for passenger vehicles in many U.S. states and Canadian provinces is around 2/32" (≈1.6 mm), but this is a minimum safety standard, not an ideal replacement point. Tests from organizations like Tire Rack and AAA show that wet stopping distances at 2/32" can be roughly double those of new tires, while 4/32" already shows noticeable performance loss compared to new. For snow and slush, many sources recommend replacing all‑season tires closer to 6/32" for reliable winter traction.
Understanding UTQG Treadwear Ratings
UTQG (Uniform Tire Quality Grading) treadwear ratings are assigned by tire manufacturers following NHTSA test procedures. A reference tire is graded 100, and other tires are driven alongside it on a standardized course for thousands of miles. If a tire earns a grade of 200, it wore at about half the rate of the reference tire; a 400 grade wore at roughly one‑quarter the rate under test conditions. However, ratings are only directly comparable within a manufacturer’s own lineup and do not guarantee any specific mileage, because real‑world driving conditions differ dramatically from the test loop.
Using Tread Depth & UTQG Together
Tread depth tells you where you are today; UTQG treadwear tells you roughly how quickly the tire will get there compared to other models from the same brand. A higher treadwear rating usually means a longer‑lasting tire, but tread depth is the real‑time safety check. Use this calculator to monitor how much usable tread you have left and pair that with UTQG and your actual mileage to judge whether a given tire model is meeting your expectations.