The RUT Validator checks whether a Chilean Rol Único Tributario has the correct check digit, applying the same modulo-11 formula used by SII.
What it is
The digit after the dash in a RUT isn't arbitrary: it results from a calculation over the digits in the number's body. A RUT with the wrong digit gets rejected by any Chilean system that validates the format.
Note: this tool checks only the number's math. It does not query SII or the Civil Registry, so it can't confirm whether the RUT really belongs to someone.
Who it's for
- Developers and QA validating Chilean customer registrations.
- Finance teams checking a RUT before issuing a document.
How the calculation works
The tool walks the RUT body's digits right to left, multiplying each by weights that cycle from 2 to 7, sums the results, and takes the remainder of dividing by 11. That remainder defines the expected digit (0-9 or K). If it matches what was typed, the RUT is valid.
How to use it
Paste the RUT (with or without dots and dash) and click Validate. To generate valid test RUTs, use the RUT Generator.
Worked example
Paste 12.345.678-5 into the field above. The tool strips the dots and dash, isolates the body 12345678, applies the cyclic weights 2 to 7 right to left, sums everything, and takes the remainder of dividing by 11. If the calculated digit matches the typed 5, the result is "Valid RUT".