Tyres / Date
Tire Date Code Calculator: DOT Week and Tyre Age
Decode the final four DOT digits or a pre-2000 three-digit code with a known decade. See an illustrative week date range, age today and general tyre-ageing guidance.
Tire Date Code Calculator: DOT Week and Tyre Age: Interprets WWYY as week and year from 2000 onwards. For WWY it uses the decade you supply, because three digits alone do not identify a decade. It maps weeks to Monday–Sunday ISO-like ranges for illustration and estimates age from your local date. Runs 100% locally in your browser with zero server file uploads.
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Reading today's date…
Find the DOT tyre identification number moulded into the sidewall. The date group is at its end and may appear on only one side; the full code may face inwards. Since 2000, the final four digits mean week and year, for example 2321 means week 23 of 2021.
Three digits mean a pre-2000 tyre. The last digit gives only the final year digit; the decade cannot be determined from these digits alone. Do not guess the decade.
Date-range assumption: Monday–Sunday ISO-like weeks, with week 1 containing 4 January. This is an illustrative mapping, not a DOT-mandated calendar; manufacturer week boundaries may differ. Week 53 is accepted only when it exists under this assumption.
General ageing guidance varies: closer inspection is commonly advised around 5–6 years, and some makers recommend replacement by 10 years. NHTSA reports manufacturer replacement advice ranging from 6 to 10 years. Michelin advises annual professional inspection after five years in service and precautionary replacement at ten years from manufacture. These are general guidelines, not a vehicle-specific recommendation.
DOT identification and ageing
NHTSA TireWise explains the last four date digits, tyre ageing and the range of manufacturer replacement recommendations, including six to ten years regardless of treadwear. This is general guidance, not a vehicle-specific assessment. https://www.nhtsa.gov/vehicle-safety/tires
Week range and age assumptions
The calculator uses Monday–Sunday weeks with week 1 containing 4 January, and accepts week 53 only in a year with 53 such weeks. The code does not specify a production day. Age is a range from the beginning to the end of the assumed week, using 365.2425 days per year and today's local calendar date.
Some manufacturer guidance distinguishes years in service from years since manufacture. Michelin advises annual professional inspection after five years in service and precautionary replacement at ten years from manufacture; the date code cannot reveal the first-use date.
How to use it
- Find the final date digits at the end of the DOT number on the tyre sidewall.
- Enter four digits, or three digits and the known production decade.
- Read the production week, assumed date range and age guidance.
Privacy & limitations
Your code and current date are processed in your browser. Nothing is uploaded.
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Frequently asked questions
Where is the date code?
Look at the end of the DOT tyre identification number moulded into the sidewall. The full date group may appear on only one side and may face inwards. For example, 2321 means week 23 of 2021.
What does a three-digit code tell me?
It identifies a pre-2000 week and a final year digit. Enter a decade only if you know it independently; the digits alone cannot distinguish 1979, 1989 and 1999.
Is this the exact manufacturing date?
No. The code identifies a week. This tool assumes Monday–Sunday weeks with week 1 containing 4 January. That is an illustrative ISO-like mapping, not a DOT calendar requirement; a manufacturer's week boundaries may differ.
Does the age mean my tyre is safe?
No. Age does not establish condition or time in service. Closer inspection is commonly advised around five to six years, and some makers advise replacement by ten years. NHTSA reports varying manufacturer replacement advice of six to ten years; consult the applicable guidance.
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