VIN reference / position 09

VIN check digit:
the quick math.

The ninth character is a transcription check for VINs governed by U.S. rules. Multiply character values by their position weights, add the products and divide by 11.

Check a VIN NHTSA reference

49 CFR 565 · CHECK DIGITPOSITION 09

CALCULATION

Σ (character value × weight)
──────────────────────────
11 → remainder = check digit

Remainder0–9

Remainder 10X

EXCLUDES POSITION 09MOD 11

Runs in your browser · no lookup

Check a VIN’s ninth character

Enter all 17 characters for an immediate U.S. check-digit calculation. This check does not send your VIN to NHTSA.

Ready when you are.Your result appears here without a network request.

Calculation steps

How the check works

Under U.S. VIN requirements in 49 CFR Part 565, the manufacturer assigns a numeric value to each VIN character except the check digit. Each position also has a weight. Multiply the values by their position weights, total the products and divide by 11. The remainder, from 0 through 9, is the check digit; remainder 10 is represented by X.

r = (\sum_{i = 1}^{17} v_{i} w_{i}) mod 11

v is the value of a character and w is the weight for its position; position 9 has weight zero.

Position weights

The weights from positions 1 to 17 are:

1—88 · 7 · 6 · 5 · 4 · 3 · 2 · 10

90 (not included)

10—179 · 8 · 7 · 6 · 5 · 4 · 3 · 2

Character values

Digits keep their face value. Letters map to values from 1 through 9: A/J=1, B/K=2, C/L=3, D/M=4, E/N=5, F=6, G/P=7, H/R=8 and S–Z (excluding U) map to 2–9 in sequence. I, O and Q are not used in standard VINs.

Open a worked example: 1HGCM82633A004352

For this VIN, the weighted total is 311. Divide 311 by 11: the remainder is 3, which matches character 9.

U.S. check-digit calculation for VIN 1HGCM82633A004352
Position	Character	Value	Weight	Product
1	1	1	8	8
2	H	8	7	56
3	G	7	6	42
4	C	3	5	15
5	M	4	4	16
6	8	8	3	24
7	2	2	2	4
8	6	6	10	60
9	3	—	0	0
10	3	3	9	27
11	A	1	8	8
12	0	0	7	0
13	0	0	6	0
14	4	4	5	20
15	3	3	4	12
16	5	5	3	15
17	2	2	2	4
Weighted total				311
311 mod 11				3

A pass is not proof of identity

A matching check digit indicates that the entered characters satisfy the U.S. calculation. It can catch a transcription mistake, but it does not establish that the vehicle is authentic, that the VIN plate has not been altered, or that the vehicle has a clean title or history. Requirements differ across markets; the U.S. check digit is not a universal authenticity test.

For manufacturer-reported vehicle attributes, use the NHTSA vPIC lookup from the VINDECODE home page.

Primary reference

Rule behind the formula

The formula and assigned weights are set out in 49 CFR § 565.15. NHTSA describes VIN structure and provides its public manufacturer data lookup through the the NHTSA VIN decoder.

VINDECODE computes the check digit locally in your browser. Vehicle attribute lookups are sent to NHTSA vPIC only when you submit a VIN on the homepage; the interactive VIN chart shows where position 9 sits.