Calculator
Tire age calculator
Tread depth tells you about wear. It says nothing about age, and rubber ages whether the tire is driven or not.
Age today
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Where to find it
On the sidewall, look for the letters DOT followed by a string of up to twelve characters. The last four are the date: two digits for the week, two for the year. The full code is often only on one side of the tire, so check the inner sidewall if you cannot find it.
DOT XXXX XXXX 2419
The rules behind the verdict
NHTSA and the tire industry recommend an annual inspection from five years of age, most vehicle and tire makers set six years as the replacement point regardless of tread, and ten years is the maximum any maker supports. Our tire safety guide covers why: tread separations, the failure mode that kills, are driven by chemical ageing rather than wear.
The math, shown
Week and year come straight from the code. The manufacture date is taken as the Monday of that week. Age is the difference between that date and today.
Questions people ask
Why do tires age if they are not driven?
Oxygen and heat break down the rubber compounds and the adhesive layers between the tread and the steel belts. This happens on a parked car and in a warehouse. A tire that has never been used but was made eight years ago has most of the ageing of one that was driven the whole time.
Does the spare tire count?
Yes, and it is usually the oldest tire on the car because nobody looks at it. A ten-year-old spare that has never touched the road should still be replaced before it is relied on.
Does age matter more in a hot climate?
Yes. Heat accelerates the chemical ageing. Tires in Arizona, Texas and Florida age faster than the same tires in Minnesota, and the tire safety guide maps where heat degradation is worst.