Chilean RUT Validator

How the RUT check digit (DV) is calculated

The RUT check digit is calculated with a modulo 11 algorithm: multiply each digit of the RUT, from right to left, by a repeating sequence of 2, 3, 4, 5, 6, 7, sum the results, and subtract the remainder of that sum divided by 11 from 11. If the result is 11 the check digit is 0; if it is 10, the check digit is the letter K; otherwise it is the number itself.

How do I calculate the RUT check digit?

To calculate the RUT check digit (DV), multiply each digit from right to left by a repeating weight sequence of 2, 3, 4, 5, 6, 7, add the products, subtract the remainder of that total divided by 11 from 11, and map 11 to 0 and 10 to K. Example: 12.345.678 gives a check digit of 5.

Steps to calculate the DV

1. Remove dots and hyphens, keeping only the RUT digits (up to 8).
2. Starting from the rightmost digit, multiply each digit by 2, then the next by 3, then 4, 5, 6, 7, repeating the cycle if there are more digits.
3. Add all the products together.
4. Divide the sum by 11 and find the remainder, then compute 11 minus that remainder.
5. If the result is 11, the check digit is 0; if it is 10, the check digit is K; otherwise the result itself is the check digit.

Formula

• digit = each individual digit of the RUT, read from right to left
• weight = the multiplier for that position, cycling through 2, 3, 4, 5, 6, 7 and repeating
• mod 11 = the remainder of the total sum divided by 11

Example RUT numbers and their check digits

Frequently asked questions

What does 'K' mean as a check digit?

K represents the value 10. Since a single digit can't show two characters, the RUT algorithm uses the letter K whenever the calculated check value equals 10, in the same way DV letters are used to keep the identifier at a fixed length.

Can this tool detect a fake RUT?

It confirms the check digit is mathematically consistent with the digits before it, which catches typos and randomly made-up numbers. It cannot confirm the RUT was actually issued by the Chilean Servicio de Registro Civil e Identificación — that requires an official lookup.

Does the RUT format matter (dots, hyphen)?

No — this tool accepts digits with or without dots and a hyphen, and formats the result automatically (e.g. 12345678 becomes 12.345.678-5). Only the digits themselves affect the calculation.

What is the difference between RUT and RUN?

RUN (Rol Único Nacional) is the number assigned to a person; RUT (Rol Único Tributario) is the same number used for tax purposes. In everyday use, and in this calculator, the two are treated identically.

This tool implements the public modulo-11 check-digit algorithm only; it does not verify that a RUT was actually issued, is active, or belongs to a real person or company. Use Chile's official Servicio de Registro Civil e Identificación for identity verification.