RUT Validator (Chile)

About this calculator

The Chilean RUT (Rol Único Tributario) / RUN check digit is computed with a modulo-11 algorithm: each digit of the number is multiplied by a cyclic weight sequence (2, 3, 4, 5, 6, 7, then back to 2…) from right to left, the products are summed, and 11 minus the sum's remainder mod 11 gives the check digit — mapped to "0" if the result is 11, and to "K" if the result is 10. This validator recomputes that digit from the number portion and compares it against the one supplied.

Chilean e-commerce and fintech businesses use this exact algorithm to validate a customer's RUT at checkout or account signup before it hits a database, while developers and accountants use it to spot typos in a RUT before it goes into an invoice, contract, or SII (tax authority) filing.