ABA Routing Number Validator

Check whether a US routing number is valid.

How to use

  1. Enter your values in the fields above.
  2. Press Calculate to see your result instantly.
  3. Use the Share button to copy a link to your result.

About this calculator

This calculator validates a 9-digit US ABA routing number using its built-in checksum: each of the nine digits is multiplied by a fixed weight (3, 7, 1, repeating), the products are summed, and a valid routing number's sum must be evenly divisible by 10. This single check digit catches most typos and transcription errors before a transfer is attempted.

Bank employees, accountants, payroll processors, and developers building ACH or wire transfer forms use it to catch invalid routing numbers before submitting a transaction, avoiding failed or misdirected payments. Enter the 9-digit routing number to check whether it passes the checksum.

Was this helpful?

Comments (0)

  • Be the first to comment.

Popular calculators

All Calculators