Tire Age Calculator From the DOT Code

You need a flashlight and, ideally, a tread depth gauge.

• Date code: on the sidewall, after the letters DOT, the last four digits. The first two are the week, the last two the year. It may be on the inner sidewall only.
• Tread depth: measured in 32nds of an inch in the main grooves. If you have no gauge, compare the tread with the wear bars in the grooves.
• Wear pattern: even, worn in the center, worn on both edges, worn on one edge, or cupped.
• Visible cracks: in the sidewall or between tread blocks.

See the tire date code guide for photos.

The tool converts the date code into an age in years and months from today. It then places the tire in a low, moderate or high age risk band. Visible cracking moves the band up.

Age guidance differs between vehicle makers and tire makers, and no single cut-off fits every tire. The tool uses conservative bands and shows them on screen. Your owner manual may give a specific recommendation, and that takes priority.

Tread wear indicators are molded into the grooves at 2/32 of an inch. When the tread is level with them, the tire is worn out. The tool marks that as replace.

Wet grip drops well before the wear bars show, so the tool also marks a caution zone above that level. If you drive often in rain or into the mountains, treat caution as a reason to shop for tires soon. See the tire care and safety guide.

The tool pairs each pattern with its most common cause.

See tire wear patterns for photos of each.

The tool cannot see inside the tire, where belt separation or old repairs may hide. It cannot detect a slow leak, a bent wheel or a bulge you did not mention. It does not know your load, speed or how the tire was stored before it was mounted.

If you see a bulge, cords, a deep cut, or the tire keeps losing air, skip the tool and call (909) 608-7699.

The tool also cannot judge a repair someone else made. A plug pushed in from the outside, a patch too close to the shoulder, or a tire that was driven flat for a mile can all look normal from the tread. If you know a tire has been repaired before, say so at the visit so we can check it from the inside.

If either score is high, get the tires inspected. We measure tread, read date codes, inspect for damage and show you what we see. If new tires are needed, we check size, load index and speed rating, and install them with balancing, a TPMS check and torque.

Same-day installation is possible when your size is in stock and a bay is open. Send a booking request or see new tires and brands.

Pressure, a tread reading and a slow walk around the car are safe home checks, and they give the tool better inputs. Leave plugging a tread puncture, dismounting a tire and programming TPMS sensors to the shop, since those need equipment and a look inside the tire.

1. Check pressure cold, before driving, using the number on the driver door jamb, not the maximum printed on the sidewall.
2. Measure tread in the inner, center and outer grooves of each tire. Enter the lowest reading.
3. Run a hand lightly across the tread. A sawtooth feel in one direction hints at alignment or missed rotations.
4. Shine a light on both sidewalls, including the inner side where curbs and road debris leave marks.
5. Read every date code, spare included. Tires on the same car often have different ages.

Heat speeds up the aging of rubber. Cars parked outside through long summers, tires baking on hot asphalt, tend to show sidewall cracking sooner than cars kept in a garage. That is why the tool asks about cracking on its own line and lets it push the age band upward.

Pressure swings in the same season. Hot pavement raises pressure while you drive, cool mornings drop it, and a tire running low flexes more and builds more heat. If a tire sits in the moderate band and you cover long freeway stretches in summer, have it looked at before the hottest months. Trailers, RVs and project cars that sit for months deserve the same attention.

The tool shows both scores so you can see where the concern sits. The higher of the two decides the next step.

Different results across the four tires are common. If only one or two need replacing, ask about matching tread depth and whether your all-wheel-drive system needs all four changed together.