VIN Check Digit Calculator
Validate a 17-character Vehicle Identification Number by checking its check digit against the standard VIN algorithm.
About this calculator
Validate a 17-character Vehicle Identification Number by verifying its check digit against the standard North American VIN algorithm.
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
- Enter the full 17-character VIN.
- Press Calculate to see whether the check digit is valid, and what digit was expected.
Tips
- This check only works reliably for North American-market VINs — the 9th-position check digit isn't used the same way worldwide.
Formula
Check digit = (Σ (value of character × position weight)) mod 11, where a result of 10 is represented as "X"