Tire Tread Life Calculator
How many kilometres or miles are left on your tires? From new and current tread depth and distance driven, find your wear rate, remaining distance to the legal or wet-safety limit and how many years until replacement.
How it works
wear rate = (new depth − current depth) ÷ distance driven · remaining distance = (current depth − limit) ÷ wear rate · years left = remaining ÷ yearly distance · total life = (new − limit) ÷ wear rate
Tires wear roughly linearly with distance for a given car, driver and road, so the tread you have already used tells you how fast the rest will go. The legal minimum in the EU, Mexico, most of Latin America and most US states is 1.6 mm (2/32″) — the height of the tread-wear bars — but braking on wet roads deteriorates sharply below about 3 mm (4/32″), and snow traction needs 4 mm or more. Measure in the main grooves at several points across each tire and use the lowest reading; uneven wear across the tread points to alignment or pressure problems that shorten life. Tires should also be replaced after about 6–10 years regardless of tread, because rubber ages.
Worked example
Tires that started at 8 mm and measure 5 mm after 30,000 km have worn 1.0 mm every 10,000 km. With 3.4 mm left above the 1.6 mm legal limit they have about 34,000 km to go — 2.3 years at 15,000 km a year — for a projected total life of 64,000 km.
Sources: NHTSA — Tires · EU Council Directive 89/459/EEC — tread depth of tyres
Frequently asked questions
How many km are left on my tires?
Divide the tread you have above the limit by your wear rate. If you have worn 3 mm in 30,000 km, each millimetre lasts 10,000 km, so 3.4 mm above the 1.6 mm limit is about 34,000 km.
What is the minimum legal tread depth?
1.6 mm (2/32″) in the EU, UK, Mexico and most US states. Some countries require more for winter tires (for example 3–4 mm in Nordic countries in winter).
When should I replace tires for safety?
Many tire makers and safety groups recommend about 3 mm (4/32″) for wet roads and 4 mm (5/32″) for snow, because stopping distances on water grow quickly below those depths.
How do I measure tread depth without a gauge?
Look for the tread-wear indicator bars in the grooves: when the tread is flush with them you are at 1.6 mm. In the US, the penny test (Lincoln's head fully visible = 2/32″ or less) and the quarter test (Washington's head visible = under 4/32″) are rough checks.
Related calculators
This calculator is for educational purposes. Double-check important results before acting on them.