Tire Size by VIN: Why the VIN Doesn't Have It
A VIN decode does not return tire size, and NHTSA's vPIC has no such field. Here is where your factory tire size lives and how to read the sidewall code.
No U.S. VIN decoder returns this, because NHTSA vPIC does not carry the field. Any site that claims otherwise is reading something other than the VIN.
No, a VIN decode does not return tire size. NHTSA's vPIC database, which powers free VIN decoders including ours, publishes 144 variables and none of them is tire size. Your factory tire size is on the tire and loading information placard on the driver's door jamb, required by FMVSS 110 (49 CFR 571.110, S4.3). vPIC's two wheel-diameter fields came back blank on all 18 VINs we tested.
How do I find the tire size from a VIN?
- Open the driver's door and look at the B-pillar, the post between the front and rear doors. The tire and loading information placard is there on most vehicles under 10,000 lb GVWR.
- Read the line headed "Size," "Original Tire Size" or "Original Size." FMVSS 110 S4.3(d) requires front, rear and spare to be listed separately, so note all three; staggered setups use different front and rear sizes.
- Write down the cold inflation pressure printed beside each size. That pressure belongs to that tire size and to this vehicle. It is not the maximum pressure molded on the sidewall.
- If the placard is not on the B-pillar, check the forward edge of the rear side door, then the rear edge of the driver's door, then the inward-facing surface next to the driver's seat. FMVSS 110 S4.3 permits those fallbacks.
- Read the size molded into the tire sidewall too, and compare. FMVSS 139 S5.5(b) requires it on each sidewall. A difference means the tires on the vehicle are not the original size.
- Decode the VIN free at free-vin-lookup.com/check to confirm model year, make, model, body class and GVWR class, then use those to find the factory tire size in the manufacturer's own fitment guide or owner's manual.
Anatomy of a tire size code, using P225/65R17 102H as the example. The size designation itself is defined by the Tire and Rim Association and equivalent bodies, which FMVSS 139 S4.1.1 references; it is not a government-issued code and it does not appear anywhere in the VIN.
| Segment | Example | What it means |
|---|---|---|
| Service type letter | P | P = P-metric, built to U.S. passenger-car standards. LT = light truck. ST = special trailer. T = temporary spare. No letter = Euro-metric, which carries a slightly different load rating than the same P-metric size. |
| Section width | 225 | Width of the inflated tire in millimeters, sidewall to sidewall, measured on its specified rim. Not the tread width. |
| Aspect ratio | 65 | Sidewall height as a percentage of section width. 65 means the sidewall is 65% of 225 mm, about 146 mm. A lower number is a shorter sidewall. |
| Construction | R | R = radial, used on nearly all modern road tires. D or a hyphen = diagonal (bias) ply. B = belted bias. ZR = radial rated above 149 mph. |
| Rim diameter | 17 | Diameter in inches of the wheel the tire mounts on. This must match the wheel exactly; it is the only part of the code you cannot change independently. |
| Load index | 102 | Coded maximum load for one tire at full inflation. 102 = 850 kg (1,874 lb). LT sizes often show two figures, such as 121/118, for single and dual rear-wheel use. |
| Speed rating | H | Maximum sustained speed the tire is rated for. S = 112 mph, T = 118, U = 124, H = 130, V = 149, W = 168, Y = 186. |
| Load range (separate marking on LT and ST tires) | Load Range E | Printed near the size rather than inside it. Indicates the tire's inflation and load capability, replacing the older ply rating. FMVSS 139 S5.5(d) requires it on LT tires. |
Where the VIN route stops for tire size
- vPIC has no tire size variable at all. Its published variable list (GetVehicleVariableList) returns 144 variables, and the only tire-related one is Tire Pressure Monitoring System (TPMS) Type, which reports only Direct or Indirect.
- vPIC's Wheel Size Front (inches) and Wheel Size Rear (inches) fields hold rim diameter, not tire size, and they returned empty on all 18 VINs we decoded, including passenger cars, pickups, an EV, a Class 8 Freightliner and five motorcycles.
- The door-jamb placard gives the original size, not the current one. FMVSS 110 S4.3(d) defines it as the size for the tires installed at the time of first purchase, so it will not reflect a later size change.
- FMVSS 110 S4.3 exempts trailers and incomplete vehicles from the placard requirement, so a utility or travel trailer may carry only the 49 CFR part 567 certification label, which gives GVWR and GAWR rather than a placard tire size.
- Vehicles over 10,000 lb GVWR and motorcycles fall under FMVSS 120 rather than 110, so their tire and rim information is presented differently. Check the certification label and the owner's manual for those.
Where to get it instead
- Tire and loading information placard on the door jamb. The authoritative source for the original tire size. FMVSS 110 S4.3 requires it on the driver's-side B-pillar of every vehicle at or under 10,000 lb GVWR except trailers and incomplete vehicles, and requires it to list front, rear and spare sizes plus the recommended cold inflation pressure for each. Source →
- The tire sidewall itself. FMVSS 139 S5.5(b) requires the tire size designation to be molded into each sidewall, along with the maximum load rating and, on LT tires, the load range letter. This tells you what is mounted right now, which is not necessarily what the vehicle came with. Source →
- Free vPIC decode at free-vin-lookup.com/check. Confirms model year, make, model, body class, drive type, GVWR class and TPMS type from the VIN. It will not give tire size, because vPIC does not carry that field. Use the decoded year, model and trim as the key for the manufacturer's fitment guide. Source →
- Owner's manual or manufacturer fitment guide. Lists original equipment tire sizes per trim and wheel option, including the spare. This is the fallback when the placard is missing, painted over or unreadable, and the only route for most trailers, which FMVSS 110 exempts from the placard requirement.
Primary sources
Open the underlying public source and verify that its scope matches the question you are asking.
- vPIC Vehicle Variable List (144 variables; no tire size field)NHTSA
- FMVSS No. 110, S4.3 — tire and loading placard content and location (GVWR 10,000 lb or less)eCFR / U.S. Department of Transportation
- FMVSS No. 139, S5.5 — required tire sidewall markings, including size designation and load rangeeCFR / U.S. Department of Transportation
- FMVSS No. 120 — tire and rim selection for vehicles over 10,000 lb GVWR and motorcycleseCFR / U.S. Department of Transportation
- vPIC DecodeVinValues APINHTSA
Tire Size by VIN: Why the VIN Doesn't Have It — questions
Are there free options to look up a VIN online?
Yes. NHTSA's vPIC decoder is free and public, and our decoder at free-vin-lookup.com/check runs on it. Neither returns tire size, because vPIC has no tire size variable. What you do get free is year, make, model, body class, engine, drive type, GVWR class and TPMS type. Use those to look up the factory tire size in the manufacturer's fitment guide.
Can I look up a vehicle's window sticker using its VIN?
Sometimes, and it can help here. Several manufacturers host original window sticker lookups by VIN, and a Monroney label often lists the original equipment tire size under standard or optional equipment. There is no federal window sticker database, coverage varies by make, and older vehicles are usually not covered. The door-jamb placard is the more reliable source.
How do I identify compatible parts for my 1998 Chevrolet Silverado?
For tires, start at the driver's door jamb placard, which lists the original front, rear and spare sizes for that exact truck. A 1998 Silverado decodes in vPIC for year, make, model, body class and GVWR class, but not tire size. If the placard is missing, the owner's manual and the GM service parts identification label list the original tire and wheel package.
How do I identify the specific GM RPO codes on my vehicle?
GM RPO codes are on the service parts identification label, usually inside the glove box or on the console lid, not in the VIN. Wheel and tire options have their own RPO codes, so that label tells you which package the truck was built with. vPIC does not decode RPO codes, and a VIN decode will not return them.
How do I find out the trim level of my vehicle?
vPIC returns Trim only sometimes. Our 2018 Prius decode returned "Two Eco/Three/Three Touring/Four/Four Touring" as one slash-separated list, and the 2013 F-150 and 2023 Model 3 decodes returned Trim blank. Trim matters for tires because wheel packages change by trim, so confirm trim from the window sticker or build sheet before ordering.
What if the tire and loading placard is missing or unreadable?
FMVSS 110 S4.3 allows fallback locations: the forward edge of the rear side door on vehicles without a driver's-side B-pillar, then the rear edge of the driver's door, then the inward-facing surface next to the driver's seat. Check all of them. If the placard is truly gone, the owner's manual lists the original tire sizes by trim.
Does a VIN give my wheel or rim size?
Not in practice. vPIC defines Wheel Size Front (inches) and Wheel Size Rear (inches) as wheel diameter, but both came back empty on all 18 VINs we decoded, including passenger cars, pickups, an EV, a Class 8 truck and five motorcycles. Rim diameter is the number just after the construction letter in the tire size, such as the 17 in P225/65R17.
How do I know if the tires on the car now are the right size?
Compare the sidewall to the placard. FMVSS 139 S5.5(b) requires the tire size designation to be molded into each sidewall, so read the code off the tire and check it against the size listed on the door jamb. They will not match if a previous owner changed sizes, and a mismatch changes load capacity, speedometer reading and correct inflation pressure.