Calculate numeric check characters.
Initialising algorithm engine for ISO 7064 MOD 11-2 Calculator...
How ISO 7064 MOD 11-2 Calculator Works?
The ISO 7064 MOD 11-2 Calculator works by processing digits left to right with the recurrence p = ((p + digit) × 2) mod 11 and picking the check value that makes the final total congruent to 1 modulo 11. A check value of 10 is written as X.
- 1Set the running value p to 0.
- 2Add the next digit to p, multiply by the radix 2, and reduce modulo 11.
- 3Repeat for every payload digit from left to right.
- 4Compute the check value c = (12 − p) mod 11.
- 5Write c = 10 as the character X, otherwise write the digit.
ISO 7064 MOD 11-2 Calculator Formula
The ISO 7064 MOD 11-2 formula is c = (12 − p) mod 11, where p is the running value after the last digit.
p₀ = 0 pᵢ = ((pᵢ₋₁ + aᵢ) × 2) mod 11 c = (12 − pₙ) mod 11, c = 10 → 'X'
aᵢis the i-th digit from the left.2is the radix r.11is the modulus M.
(0 + 0) × 2 mod 11 = 0 (0 + 7) × 2 mod 11 = 3 (3 + 9) × 2 mod 11 = 2 (2 + 4) × 2 mod 11 = 1 Check value = (11 + 1 − 1) mod 11 = 0 Check character = 0 Complete string = 07940
ISO 7064 MOD 11-2 Calculator Conversion Table
The ISO 7064 MOD 11-2 conversion table maps check values 0–10 to output characters and lists sample payloads.
| Check value | Character | Sample payload | Check character | Complete string |
|---|---|---|---|---|
| 0 | 0 | 0794 | 0 | 07940 |
| 1 | 1 | 079 | X | 079X |
| 2 | 2 | 000000021825009 | 7 | 0000000218250097 |
| 3 | 3 | 000000012146438 | X | 000000012146438X |
| 4 | 4 | 1234567890 | 8 | 12345678908 |
| 5 | 5 | 11010519491231002 | X | 11010519491231002X |
| 6 | 6 | 44052418800101001 | 4 | 440524188001010014 |
| 7 | 7 | 123 | 1 | 1231 |
| 8 | 8 | 5 | 2 | 52 |
| 9 | 9 | 99999 | 4 | 999994 |
| 10 | X | 20240101 | 4 | 202401014 |
What is ISO 7064 MOD 11-2 Calculator?
An ISO 7064 MOD 11-2 Calculator is a tool that computes the single numeric check character defined by ISO/IEC 7064 for digit strings. The output is a digit 0–9 or the letter X.
The International Standard Name Identifier (ISNI), the Open Researcher and Contributor ID (ORCID), and the 18-digit Chinese Resident Identity Card number all end with a MOD 11-2 check character.
MOD 11-2 detects all single-digit errors and all adjacent transpositions.
What are the uses of ISO 7064 MOD 11-2 Calculator?
There are 4 main uses of the ISO 7064 MOD 11-2 Calculator, including ORCID iDs, ISNI codes, and Chinese ID numbers.
- ORCID iD validation: Research platforms check the 16th character of researcher iDs.
- ISNI checks: Libraries and rights agencies validate public identity identifiers.
- Chinese resident ID numbers: Onboarding systems check the 18th character of PRC identity numbers.
- Standards conformance tests: Developers compare code output with ISO 7064 annex examples.