The Penny Test for Tire Tread Depth

The Problem

Worn tires are the #1 preventable cause of wet-weather accidents. You can't tell tread depth by looking.

The Hack

Take a penny, insert it into the tread groove with Lincoln's head pointing down. If you can see ALL of Lincoln's head, tread is below 2/32 inch and tires need immediate replacement.

Why It Works

The distance from penny edge to the top of Lincoln's head is exactly 2/32 inch — the minimum legal tread depth in all 50 states. It's a precision measurement tool in your pocket.

Pro Tips

• Check all 4 tires in multiple spots — wear can be uneven
• Inner/outer edge more worn = needs alignment
• Center more worn than edges = overinflated
• Quarter test (Washington's head) measures 4/32 — the recommended safe minimum