Product Standards decoder

Tyre Code Decoder

Decode tyre size markings, DOT date codes, and bundled DOT plant-code rows such as 225/45 R17 94W, DOT 1424, and DOT 1AP 1424.

Inputs

Results

Tyre marking visual
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Decoded result
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Confidence
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Segment breakdown

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Matched fields

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Reference Table

InputDecoded result
225/45 R17 94W225 mm width, 45% aspect ratio, 17 inch rim, load 94, speed W
205/55R16 91V205 mm width, 55% aspect ratio, 16 inch rim, load 91, speed V
195/65 R15 91H195 mm width, 65% aspect ratio, 15 inch rim, load 91, speed H
265/70R17 115T265 mm width, 70% aspect ratio, 17 inch rim, load 115, speed T
LT265/70R17 121/118S265 mm width, 70% aspect ratio, 17 inch rim, load 121/118, speed S

Code Structure

Tyre Code Decoder splits the marking into recognized segments, explains what each segment means, and flags ambiguous or incomplete inputs.

How To Decode

  1. Enter the marking exactly as printed, including spaces, hyphens, suffixes, and units.
  2. Review the segment breakdown first, then compare candidates in the result table when more than one interpretation is possible.
  3. Use the cited standard or manufacturer datasheet before making safety, procurement, or compliance decisions.

Sources And Limits

DOT plant code and manufacturer metadata from martinoak/dot-code-parser (MIT), plus tyre size parser taxonomy from Gan4x4/tyresize (MIT), cross-checked against NHTSA TireWise guidance; verified 2026-08-30.

Decode logic

  • Read a size marking as width, aspect ratio, construction letter, rim diameter, then load index and speed symbol as printed (225/45 R17 94W).
  • Read load and speed symbols as markings only, never as permission to exceed the tyre or vehicle ratings.
  • Read a 4-digit DOT date as production week plus year: DOT 1424 is week 14 of 2024; a plant code prefix (1AP) names the factory via the bundled NHTSA rows.
  • Use the decoded marking as a sidewall reading aid and verify age, condition, fitment, and pressure against the tyre label and vehicle placard.

Related decoders

FAQs

What does the W mean in 94W?

W is the speed symbol paired with load index 94. Read both as printed markings and follow the vehicle placard, not the symbol alone.

Which year and week is DOT 1424?

DOT 1424 is production week 14 of 2024. The date states when the tyre was made, not how much life remains.

What is the 1AP in DOT 1AP 1424?

1AP is the DOT plant code naming the factory (Michelin, Ardmore, Oklahoma, USA in the bundled rows) ahead of the 1424 date. Confirm recalls against NHTSA records.

What does the R mean in R17?

R marks radial construction ahead of the 17-inch rim diameter. It is a construction code, not a size ranking.