Tire Age Calculator from the DOT Code

How we calculate

Enter the DOT code from the tire sidewall, or only its last four digits. Since 2000 the date code has four digits: the first two are the week of manufacture and the last two are the year. A code ending in 2319 means week 23 of 2019. The calculator shows the week, the year, the start date of that week, and the age of the tire today in years, months, and days. Today's date comes from your device clock.

How we calculate: we read the last four digits, take the first two as the week number from 01 to 53, and take the last two as the year after 2000. We use the Monday of that ISO week as the manufacture date. ISO week 1 is the week that contains January 4. The age is today's date minus that Monday. Whole years and months are counted on the calendar, and the decimal age is the number of days divided by 365.2425.

For example, code 2319 starts on Monday, June 3, 2019. On November 11, 2026 that tire is 2,718 days old, which is 7 years and 5 months, or about 7.44 years. The tire could have been made on any day of that week, so the real age can be up to six days less than shown.

Codes with only three digits come from tires made before 2000. They do not state the decade, so the tool does not guess and shows a message instead. Week 53 is accepted only for years that have 53 ISO weeks. A code that points to a future date is rejected.

Age alone does not tell you whether a tire is fit for use. Storage, sunlight, load, inflation, and repairs all affect the rubber. Some vehicle and tire makers publish age recommendations. Read the owner's manual and the tire maker's guidance, and have an installer inspect tires of any age.

Frequently asked questions