Enter a RUT with or without its check digit (DV) to calculate or validate it — dots and hyphen are formatted automatically.
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.
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.
Multiply each digit from right to left by weights cycling 2,3,4,5,6,7,2,3,4,5,6,7..., sum them, then compute 11 minus (sum mod 11). For 12345678, that gives check digit 5, so the full RUT is 12.345.678-5.
The check digit becomes 0 -- 11 minus (sum mod 11) equals 11 only when the sum mod 11 is 0, so that 11 is capped to 0.
The check digit becomes the letter K, since Chilean RUT check digits use K to represent 10 instead of a two-digit number.
6 -- so the formatted RUT is 7.654.321-6.
1.000.005-K -- verified by computing 11 minus (weighted sum mod 11), which equals 10, becoming K.
1.000.013-0 -- the weighted sum mod 11 comes out to 0, so 11 minus 0 is capped to 0.
Starting from the rightmost digit, multiply by 2, then 3, 4, 5, 6, 7, then wrap back to 2 for the next digit, and so on leftward.
Yes -- it strips periods and spaces before parsing, then re-formats the digits with dots and adds the dash and check digit itself.
| RUT | Check digit (DV) | Formatted |
|---|---|---|
| 12345678 | 5 | 12.345.678-5 |
| 76192083 | 9 | 76.192.083-9 |
| 5126663 | 3 | 5.126.663-3 |
| 1 | 9 | 1-9 |
| 9999999 | 3 | 9.999.999-3 |
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.
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.
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.
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.
Last updated: 2026-08-17