How to Read a Chevrolet VIN Number, Position by Position
A Chevrolet VIN from the 1981 model year on has 17 characters in three blocks. Positions 1 through 3 identify the manufacturer and where the vehicle was built, such as 1G1 on many U.S.-built Chevrolet cars. Positions 4 through 9 describe the vehicle line, body, and engine, and end with a check digit. Positions 10 through 17 give the model year, the assembly plant, and the production serial number. Reading those blocks tells you who built the vehicle, broadly what it is, its model year, and where it was assembled. It won't tell you the paint color, axle ratio, or option packages; those come from factory equipment records tied to the VIN. The letters I, O, and Q never appear in a modern VIN, so a character that looks like an O is a zero.
Where to find the VIN
Look at the base of the windshield on the driver's side, where a plate is readable from outside, and on the label on the driver's door jamb. The same number appears on the title, registration, and insurance card, and on many Chevrolets it is also printed on the glove box option label. All of them should match exactly. If any copy differs by even one character, sort that out before relying on anything decoded from it.
The 17 positions on a Chevrolet VIN
| Position | What it records | Notes for Chevrolet |
|---|---|---|
| 1 | Country of final assembly | 1 = United States, 2 = Canada, 3 = Mexico, K = South Korea |
| 2 | Manufacturer | G = General Motors on North American-built Chevrolets; Korean-built models start with KL instead |
| 3 | Make or vehicle type | Read with positions 1 and 2: 1G1 is a Chevrolet passenger car, 1GC a Chevrolet truck, 1GN a Chevrolet SUV or multipurpose vehicle |
| 4–7 | Vehicle attributes | Model line, series, and body style, and on some vehicles the restraint system or weight class; GM's assignments differ between cars and trucks and have changed over time |
| 8 | Engine | GM generally uses this position for the engine code |
| 9 | Check digit | Calculated from the other 16 characters |
| 10 | Model year | A letter or number on a 30-year cycle |
| 11 | Assembly plant | One character per plant |
| 12–17 | Production sequence | The vehicle's serial number within its run |
Positions 4 through 8 are where reading by hand gets harder. The same character can mean different things on a Silverado and a Malibu, and GM has revised these assignments across generations, so a chart has to match both the vehicle type and the model year.
Decoding the model year character
Position 10 cycles through letters and digits, skipping I, O, Q, U, Z, and zero. The codes repeat every 30 years, so a B can mean 1981 or 2011; the vehicle itself almost always makes the answer obvious.
| Code | First cycle | Second cycle |
|---|---|---|
| A | — | 2010 |
| B | 1981 | 2011 |
| C | 1982 | 2012 |
| D | 1983 | 2013 |
| E | 1984 | 2014 |
| F | 1985 | 2015 |
| G | 1986 | 2016 |
| H | 1987 | 2017 |
| J | 1988 | 2018 |
| K | 1989 | 2019 |
| L | 1990 | 2020 |
| M | 1991 | 2021 |
| N | 1992 | 2022 |
| P | 1993 | 2023 |
| R | 1994 | 2024 |
| S | 1995 | 2025 |
| T | 1996 | 2026 |
| V | 1997 | 2027 |
| W | 1998 | 2028 |
| X | 1999 | 2029 |
| Y | 2000 | 2030 |
| 1–9 | 2001–2009 | 2031–2039 |
The model year is the year GM assigned to the vehicle, not the date it was built or sold. A truck assembled in the fall of 2024 can carry an S for the 2025 model year.
Checking the check digit by hand
The ninth character is calculated from the other 16, which makes it a quick test for a mistyped VIN.
- Convert each letter to a number: A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8; J=1, K=2, L=3, M=4, N=5, P=7, R=9; S=2, T=3, U=4, V=5, W=6, X=7, Y=8, Z=9. Digits keep their own value.
- Multiply each position by its weight. From position 1 to 17 the weights are 8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2.
- Add the 17 results and divide by 11. The remainder is the check digit, and a remainder of 10 is written as X.
If your result doesn't match position 9, a character was most likely copied wrong. A matching check digit only proves the number is internally consistent. It says nothing about whether the VIN belongs to the vehicle in front of you, so compare the plates, labels, and paperwork as well.
What reading the VIN won't tell you
A VIN is an identity number, not an option list. Basic decoding covers the manufacturer, model year, plant, and the attributes the VIN encodes, such as body style and engine. Many of the details owners care about aren't in those 17 characters at all:
- Option packages such as Z71, and often the exact trim
- The rear axle ratio, and whether a G80 locking differential was installed
- Trailering equipment, paint color, and interior trim
Those details live in VIN-specific factory records as RPO codes. On our VIN lookup, a Chevrolet VIN first shows decoded basics such as year, model, body, and engine where available, then the original window sticker when one exists or the RPO build sheet when that record is available. Some VINs return neither, and information varies by VIN, model year, market, and source availability. To see what a decoder returns and where it stops, read about the Chevrolet VIN decoder; for the option codes themselves, see Chevrolet RPO Codes by VIN.
One more limit: the 17-character format starts with the 1981 model year. Older Chevrolets use shorter numbers with different rules, explained in our classic Chevrolet VIN decoder.