Tire Tread Life Calculator
Miles left before your tires hit the wear bars.
Enter your values
Enter the tread depth when new in /32 in.
Enter the current tread depth in /32 in.
Enter the miles driven on these tires in mi.
Enter the miles you drive per month in mi.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Miles remaining
- 24,000 mi
- Months remaining
- 24 months
- Wear rate
- 0.167 /32 in per 1,000 mi
- Total expected life
- 48,000 mi
- Status
- Serviceable
Quick answer
Tread life is the usable tread above the legal limit divided by the wear rate, where wear rate is tread lost per 1,000 miles so far.
Miles left = (current − 2/32) ÷ (worn ÷ miles driven)
At a glance
| What it does | Miles left before your tires hit the wear bars. |
|---|---|
| Category | Auto |
| Inputs needed | Tread depth when new, Current tread depth, Miles driven on these tires, Miles you drive per month |
| Main output | Miles remaining |
| Formula | Miles left = (current − 2/32) ÷ (worn ÷ miles driven) |
| Cost | Free — no sign-up, no download |
How to use the Tire Tread Life Calculator
- 1Measure tread depth in the main groove with a gauge or a quarter.
- 2Enter how many miles the tires have covered.
- 3Enter your monthly mileage to convert the answer into months.
Inputs explained
- Tread depth when new(/32 in)
- Enter the tread depth when new in /32 in.
- Current tread depth(/32 in)
- Enter the current tread depth in /32 in.
- Miles driven on these tires(mi)
- Enter the miles driven on these tires in mi.
- Miles you drive per month(mi)
- Enter the miles you drive per month in mi.
Worked example
Using the values the calculator loads with:
Inputs
- Tread depth when new10 /32 in
- Current tread depth6 /32 in
- Miles driven on these tires24000 mi
- Miles you drive per month1000 mi
Results
- Miles remaining24,000 mi
- Months remaining24 months
- Wear rate0.167 /32 in per 1,000 mi
- Total expected life48,000 mi
- StatusServiceable
Frequently asked questions
What tread depth is illegal?
2/32 of an inch (1.6 mm) is the legal minimum in the US and most of Europe, and it is marked by the moulded wear bars in the grooves.
Why replace at 4/32?
Wet stopping distance and aquaplaning resistance fall off steeply below 4/32 in, so many tire shops recommend replacing before the legal limit.
What do I need to enter into the Tire Tread Life Calculator?
Just 4 values: tread depth when new, current tread depth, miles driven on these tires, miles you drive per month. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Tire Tread Life Calculator work out the answer?
Tread life is the usable tread above the legal limit divided by the wear rate, where wear rate is tread lost per 1,000 miles so far. It applies the formula Miles left = (current − 2/32) ÷ (worn ÷ miles driven) and shows the working so you can check each step by hand.
Is the Tire Tread Life Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.