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VIN Check Digit Calculator

Validate a 17-character Vehicle Identification Number by checking its check digit against the standard VIN algorithm.

About the VIN Check Digit Calculator

Validate a 17-character Vehicle Identification Number by verifying its check digit against the standard North American VIN algorithm.

How the VIN Check Digit Calculator works

The 9th character of a North American VIN is a check digit computed from all 17 characters using a weighted sum: each character is converted to a numeric value (letters via a standard transliteration table), multiplied by a fixed position weight, summed, and reduced modulo 11. This lets you catch typos or confirm a VIN is well-formed before using it, though it can't confirm the VIN belongs to a real vehicle.

How to use the VIN Check Digit Calculator

  1. Enter the full 17-character VIN.
  2. Press Calculate to see whether the check digit is valid, and what digit was expected.

Tips for the VIN Check Digit Calculator

  • This check only works reliably for North American-market VINs — the 9th-position check digit isn't used the same way worldwide.

Formula used by the VIN Check Digit Calculator

Check digit = (Σ (value of character × position weight)) mod 11, where a result of 10 is represented as "X"

Example: VIN Check Digit Calculator

Validating the VIN 1HGCM82633A004352

  • VIN: 1HGCM82633A004352

Result: Valid — expected check digit "3" matches position 9

Transliterating and weighting all 17 characters and reducing the sum modulo 11 produces a check digit of 3, which matches the 9th character of this VIN.

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