What's the minimum safe tread depth?
Legally, 2/32" is minimum, but safety experts recommend replacing at 4/32" for adequate wet-weather performance. Below 4/32", hydroplaning risk increases significantly.
Automotive
Tire Wear & Replacement Calculator
Predict how many months remain before your tires reach minimum safe tread depth and plan out the cost of new tires.
Plan Your Next Tire Purchase
Avoid sudden tire expenses—see when you’ll need replacements.
$
What this calculator does
A tire wear and replacement calculator estimates remaining tire life based on current tread depth and usage patterns. Understanding when tires need replacement is critical for safety—worn tires significantly increase stopping distances and hydroplaning risk.
How it works
You input your current tread depth (measured with a gauge or the penny test), original tread depth, and monthly mileage. The calculator determines wear rate and projects when tread will reach the minimum safe depth of 2/32 inches.
Formula
Remaining Tread = Current Depth − Minimum Safe Depth (2/32"). Wear Rate = (Original − Current) ÷ Miles Driven. Remaining Miles = Remaining Tread ÷ Wear Rate. Months Until Replacement = Remaining Miles ÷ Monthly Mileage.
Tips for using this calculator
- Replace tires at 4/32" for wet-weather safety, not just 2/32" minimum
- Check tread depth monthly using a tread depth gauge or the penny test
- Uneven wear indicates alignment or inflation problems
- Rotate tires regularly to maximize even wear
- Consider all-season vs. seasonal tires based on your climate
Frequently asked questions
How do I measure tread depth without a gauge?
Use the penny test: insert a penny with Lincoln's head down. If you can see the top of his head, tread is below 2/32" and tires need immediate replacement.
Why do my tires wear unevenly?
Uneven wear usually indicates alignment issues, improper inflation, or worn suspension components. Have the vehicle inspected and correct the issue before replacing tires.