Calculate numeric remainders and check values.
Initialising algorithm engine for Modulus 97 Calculator...
How Modulus 97 Calculator Works?
The Modulus 97 Calculator works by dividing the full number by the prime 97 and returning the remainder or a check value derived from the remainder. Large numbers are processed in chunks so the calculation never overflows.
- 1Read the payload as one decimal integer.
- 2Split long payloads into chunks of 9 digits and carry the remainder forward into each chunk.
- 3Compute the remainder r = N mod 97.
- 4Output r, 97 − r, or 98 − (N × 100 mod 97), based on the selected scheme.
- 5Pad the result to 2 digits.
Modulus 97 Calculator Formula
The Modulus 97 formula is r = N mod 97, and the 3 common check values are r, 97 − r, and 98 − (100·N mod 97).
r = N mod 97 Belgian style: check = r (00 becomes 97) Complement: check = 97 − r ISO 7064 97-10: check = 98 − ((N × 100) mod 97)
Nis the payload as an integer.ris the remainder 0–96.
1234567890 mod 97 = 2 Belgian style check = 02 Complement check = 97 − 2 = 95 ISO 7064 check = 98 − (6) = 92
Modulus 97 Calculator Conversion Table
The Modulus 97 conversion table shows remainders and the 3 check value styles for sample payloads.
| Payload | N mod 97 | Remainder style | 97 − r | ISO 7064 97-10 |
|---|---|---|---|---|
| 1234567890 | 2 | 02 | 95 | 92 |
| 5390075470 | 34 | 34 | 63 | 93 |
| 97 | 0 | 97 | 97 | 01 |
| 1000000 | 27 | 27 | 70 | 17 |
| 999999999999 | 49 | 49 | 48 | 48 |
| 3214282912 | 23 | 23 | 74 | 29 |
| 1 | 1 | 01 | 96 | 95 |
What is Modulus 97 Calculator?
A Modulus 97 Calculator is a tool that computes the remainder of a number divided by 97 and converts the remainder into a 2-digit check value. 97 is the largest prime below 100, so a 2-digit check covers almost all of the 100 possible values.
Modulus 97 checks detect all single-digit errors, all adjacent transpositions, and about 99% of other random errors. International Bank Account Numbers (IBAN), Belgian bank accounts, Legal Entity Identifiers (LEI), and RF creditor references use Modulus 97.
What are the uses of Modulus 97 Calculator?
There are 4 main uses of the Modulus 97 Calculator, including IBAN checks, Belgian account numbers, and structured references.
- IBAN check digits: Payment teams compute the 2 digits at positions 3 and 4 of an IBAN.
- Belgian account control: Belgian banks append N mod 97 to 10-digit account bases.
- Structured payment references: Creditors build RF references and Belgian structured communications (+++ / +++) with mod 97.
- Large-number remainders: Developers check big-integer remainder code against a known reference.