whats the size of the drivers license barcode

A driver’s license barcode is usually a PDF417 2D barcode , and its physical size varies by state and card design. In practice, it’s often around a few centimeters wide and tall enough to fit multiple rows of encoded data.

Typical size

For PDF417, the barcode’s printed size depends on the number of rows/columns used and the scan requirements, not one universal dimension. A common minimum design rule is a narrow module width of 9.5 mils and bar height about 3 times that width, with quiet zones around the symbol.

What’s on it

Most newer driver’s licenses have both a 1D barcode and a 2D barcode, and the 2D one typically stores the license data in encoded form. The barcode is usually placed on the back of the card.

Practical answer

If you mean the barcode printed on a standard U.S. driver’s license, the safest short answer is: it is not a fixed size, but typically a PDF417 barcode sized to fit the card’s back layout. If you need the exact dimensions for a specific state, the state’s card standard or DMV design spec is the right source.

TL;DR: Driver’s license barcodes are usually PDF417 codes, and their size varies by jurisdiction rather than following one universal measurement.