# How to Measure Tire Tread

On This Page

## What is the optimal tread for a tire?

The minimum legal limit for tire tread depth is 2/32 of inch but it’s best not to wait that long to replace your tires. If a tire is less than 3/32 of an inch, it’s time to get new tires.

## What ways are there to measure the tire’s tread?

There are a few different ways to tell if your tire tread isn’t up to par, from simple visuals using a coin to handy tools that will tell you the tread. Here is how you can measure your tire’s tread.

### The Penny Test

The penny test (shown below) is the easy way to check a tire tread’s depth when you don’t have a depth gauge. If you place a penny in your tire’s tread groove with Lincoln’s face down and can see all of his face it’s time for new tires. But as you can see in the video, even 2/32 of an inch of tire tread isn’t a great idea.

Mark Herreid/Shutterstock

### The Quarter Test

You can do the same test with a quarter to measure tire tread. If you can see Washington’s head, you have around 4/32 of tire tread left and you should consider buying new tires soon.

### Tire Tread Depth Gauge

You can pick up a tire tread depth gauge at any auto parts store. A tire tread depth gauge costs about \$5. Measure the tread depth about 1 in. from each edge and the depth of the center tread. They should all be the same.

### Tread Wear Indicator

Tread wear indicators or wear bars are located at the base of tire grooves. They rise from the grooves and when they’re even with the tire, it’s time to replace your tires.

## When to Replace Tires

Most drivers ignore their tires until it’s too late. Then they have to spend big bucks to replace them. However, you can diagnose tire problems and correct them early by performing three critical tire maintenance chores: checking the tire pressure, measuring the tread depth regularly, and rotating tires every 6,000 miles.