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Tread Depth Gauge
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Measurement
How to Measure Tire Tread Depth (Gauge Method): Accurate Steps and Pro Tips
2026-01-05•By TireCheck Team
How to Measure Tire Tread Depth (Gauge Method): Accurate Steps and Pro Tips
If you want accuracy and repeatability, a tire tread depth gauge beats any coin test. It lets you measure in 32nds of an inch (or millimeters) and track changes over time, which helps you spot alignment, inflation, or suspension issues early.
What You Need
•A simple tread depth gauge (mechanical) or a digital gauge
•A flashlight (optional but helpful)
Step-by-Step: Measuring the Right Way
1.Park safely on a level surface.
2.Inspect the tire for obvious damage (cuts, bulges, exposed cords).
3.Choose the main grooves (not small sipes).
4.Place the gauge base flat on the tread blocks and press the probe into the groove until it bottoms out.
5.Record the reading.
How Many Measurements Should You Take?
For a practical at-home check:
•3 positions across the tire: inner / center / outer
•2–3 positions around the tire: front / back / (optional middle)
Write down the lowest reading. The lowest spot is what sets your safety margin.
How to Interpret the Numbers
Common decision thresholds:
•2/32" (1.6 mm): replace immediately
•4/32" (3.2 mm): plan replacement for better wet performance
•6/32" (4.8 mm): consider as a planning threshold for frequent snow driving
Full explanation: Minimum Tire Tread Depth: Legal vs Safe
Spotting Wear Patterns
Use your inner/center/outer readings to identify likely causes:
•center lower than shoulders: possible over-inflation
•both shoulders lower than center: possible under-inflation
•one shoulder significantly lower: alignment/camber issues
•alternating high/low readings around the tire: possible cupping from suspension wear
Gauge Method vs Penny/Quarter Tests
Coin tests are fine for quick checks:
But for maintenance planning and early problem detection, the gauge method is the better choice.
Quick Next Steps
•Learn the measurement units: How to Read Tire Tread Depth (32nds and mm)
•Get the foundation overview: The Ultimate Guide to Tire Tread Depth and Safety
•Run a quick check on the homepage: Check Tire Tread with TireCheck