German IBAN Calculator – Bank Code + Account Number to IBAN
Enter a German bank code (BLZ) and account number to build the IBAN. Free, no signup — the calculation runs entirely in your browser.
Last reviewed: · Source: ISO 13616, ISO 7064, Deutsche Bundesbank
How it works
The German IBAN is assembled from three parts and a two-digit checksum:
•Country code — always DE for Germany.
•Bank code (BLZ) — the 8-digit Bankleitzahl of your bank or branch.
•Account number — up to 10 digits, left-padded with zeros to a fixed length of 10.
•Check digits — two digits computed from the rest of the IBAN with MOD-97 (ISO 7064), so a single typo is caught.
Honest limits: this calculator implements only the public standard formula from the Bundesbank BLZ dataset. It cannot apply the bank-specific IBAN conversion rules from the Bundesbank rule file (which requires registered access). A few banks issue IBANs that deviate from the standard formula, so treat the result as a strong guide — not a guarantee — and confirm it with your bank.
Validate an existing IBAN
Already have an IBAN? Use the free IBAN Checker to verify its length, country format and the ISO 7064 MOD-97 check digit — for any of the 89 IBAN countries.
Need another country? See the IBAN structure by country directory — this calculator supports Germany (DE) only.
Frequently asked questions
Is this the official IBAN for my account?
It is the IBAN produced by the public German standard formula (BLZ + account number + MOD-97 check digits). For most accounts this matches the official IBAN, but some banks apply their own deviating Bundesbank conversion rules. Always verify the result against your bank statement or online banking before using it.
What is a Bankleitzahl (BLZ)?
The Bankleitzahl (bank code) is an 8-digit number that identifies a German bank or branch. In a German IBAN it sits right after the two check digits (characters 5–12). The Deutsche Bundesbank maintains the official list of active bank codes.
Where do I find my BLZ and account number?
Both appear on older bank cards, cheques and account statements. In online banking your IBAN is shown directly; the BLZ is characters 5–12 of that IBAN and the account number is the final 10 digits.
Can I calculate IBANs for other countries?
Not with this tool — it implements the German (DE) formula only. Other countries build their national account part (BBAN) differently. See our IBAN structure directory for how each country’s IBAN is composed.
Is my data uploaded anywhere?
No. The calculation runs entirely in your browser using client-side JavaScript. Your bank code and account number are not sent to our servers, not stored and not logged.