Semi truck VIN decoder
Enter a 17-character VIN. You get the model year, make, model, body class, GVWR class and engine from NHTSA's database, plus a check-digit test and a CDL hint.
Updated October 2026 · Free, no signup
How the decoder works
The decoder does two things. First, it checks the VIN itself: 17 characters, none of the letters I, O or Q, and a 9th-character check digit that matches the other 16. That catches most typos before anything is looked up.
Then it asks NHTSA's vPIC (Product Information Catalog and Vehicle Listing) service to decode it. vPIC is built from the data manufacturers file with NHTSA under 49 CFR Part 565, and it's free to use.
Source: NHTSA vPIC · checked 2026-10
What each part of a VIN means
| Positions | Meaning | EXAMPLE |
|---|---|---|
| 1-3 | World manufacturer identifier | 1FU = a US-built heavy truck maker |
| 4-8 | Vehicle descriptor: series, cab, axles, engine | Model and configuration |
| 9 | Check digit | 0-9 or X |
| 10 | Model year | C = 2012, D = 2013 ... |
| 11 | Assembly plant | Plant code |
| 12-17 | Production sequence | Serial number |
The check digit, explained
Each character gets a value (letters map to numbers), each position gets a weight, and the weighted sum is divided by 11. The remainder, or X for 10, should equal the 9th character. A mismatch doesn't always mean fraud, but it always means look again, especially on a used truck before money changes hands.
The CDL hint
vPIC returns a GVWR class. Classes 7 and 8 start above 26,000 lb, so the truck alone needs a Class B CDL, or Class A with a heavy trailer. Class 6 and below top out at 26,000 lb. The class is a range, so confirm the exact number on the door sticker and run it through the CDL checker. That's the line we use for box trucks too: we dispatch 26 ft box trucks, most of them built right at 26,000 lb GVWR.
Trailers have VINs too
Trailers built for US roads carry their own 17-character VIN, usually on a plate at the front of the trailer or on the frame rail. The decoder reads them the same way: manufacturer, trailer type, model year and, often, the GVWR class. That's handy when a lease, a title or an insurance card has a trailer VIN you need to confirm against the plate.
Buying a used truck
Decode the VIN from the truck itself, not just the listing, and compare it with the title and registration. Then check for liens, get the maintenance records and an inspection, and run the payment through the semi truck payment calculator before you sign.
Questions about this calculator
How do I decode a semi truck VIN?
Enter the 17 characters in the decoder. Each section of a VIN means something: the first three identify the manufacturer, characters 4 through 8 describe the vehicle, the 9th is a check digit, the 10th is the model year, the 11th the plant, and the last six the serial number. The decoder reads all of it from NHTSA's database.
Can a VIN tell me the GVWR?
It gives the GVWR class, a weight range such as Class 8 (33,001 lb and above). The exact GVWR is printed on the door jamb sticker. For CDL and weight questions, use the sticker number.
What does a check digit error mean?
The 9th character is calculated from the other 16. If it doesn't match, a character was probably typed wrong, often a 0 for an O or a 1 for an I (VINs never use I, O or Q). Recheck the VIN on the truck itself, especially before you buy.
Is this VIN decoder free?
Yes. It uses NHTSA's vPIC service, a free public database built from the information manufacturers file with NHTSA. We don't store the VINs you look up.
Does a VIN decoder show accident or title history?
No. A decoder shows how the truck was built. Accident, lien and title history come from title records and paid history reports. Before buying a used truck, check the title for liens and get an inspection.
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