What does a Romanian CNP encode?

The first digit encodes sex and century, the next six are the date of birth, two digits give the county (județ), three are a serial, and the final digit is a modulo-11 checksum.

How is the CNP check digit calculated?

Multiply the first twelve digits by the constant weights 2,7,9,1,4,6,3,5,8,2,7,9, sum them, and take the sum modulo 11. If the remainder is 10 the check digit is 1, otherwise it is the remainder.

Is my CNP sent to a server?

No. The decoder runs entirely in your browser with client-side JavaScript — your CNP is never uploaded or stored.

Romania CNP Decoder

Decode birth date, sex and county from a Romanian CNP.

Romanian CNP decoder

A Romanian CNP (Cod Numeric Personal) is 13 digits that encode a person’s sex and century of birth, their date of birth, the county where the number was issued, a serial, and a check digit. This decoder reads each field and verifies the modulo-11 checksum.

Everything runs in your browser, so the CNP you enter is never uploaded. This is a structure and checksum decoder — it does not confirm the number is registered.