Chinese ID Checksum Calculator
Calculate or verify the final checksum character of a mainland Chinese resident ID locally using GB 11643-1999. Input is not stored.
Enter ID number
Used only to calculate the checksum; never saved to drafts, shared links, or network requests.
Verification result
Enter 17 or 18 characters to see the result.
Calculated checksum—
Standard full number
—About Chinese ID Checksum Calculator
Enter the first 17 digits to calculate the final checksum character, or enter a complete 18-character number to verify it. The calculation follows GB 11643-1999 and runs only in this browser.
Does a valid checksum prove the identity number is real?
No. The checksum only detects transcription errors. It does not verify that the number was issued, that the date or address is valid, or that it belongs to a person. Do not enter an ID number you do not have permission to process.