Soundex Calculator

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Soundex Coding

With Soundex, the “sound” of names — the phonetic sound, to be exact — is coded. This is of great help, since it avoids most problems of misspellings or alternate spellings.

For example: Scherman, Schurman, Sherman, Shireman, and Shurman are indexed together as NARA Soundex code S655. Surname Soundex indexing is not alphabetical, but is listed by the letter-and-number code. If several surnames have the same code, their index cards are arranged alphabetically by given name — for example, S655 Arthur, S655 Betsy, S655 Charles.

I. Russell (NARA) Soundex Coding

The Russell Soundex system is used by many indexes at the U.S. National Archives and Records Administration (NARA), including indexes to Census Records, Passenger Lists, and Naturalization Records.

In the 1930s, the Work Projects Administration (WPA) produced a complete Soundex index of the 1880, 1900, 1910 (partial), 1920, and 1930 (partial) censuses. The census information was copied onto file cards, alphabetically coded, and filed by state.

NARA Soundex coding rules:

1. Coding consists of a letter followed by three numerals (for example L123, C472, S160).
2. The first letter of a surname is not coded; it is retained as the initial letter.
3. A, E, I, O, U, Y, W, and H are not coded.
4. Double letters are coded as one letter (as in Lloyd).
5. Prefixes such as van, Von, Di, de, le, D, dela, or du are sometimes disregarded in coding.
6. Code the following letters to three digits, using 0 at the end if needed.

For additional Russell Soundex information, see The Source: A Guidebook of American Genealogy, by Arlene Eakle and Johni Cerny.

II. Daitch-Mokotoff Soundex Coding

The Daitch-Mokotoff Soundex system was created by Randy Daitch and Gary Mokotoff of the Jewish Genealogical Society (New York), who concluded that the system developed by Robert Russell in 1918 — still used today by NARA — does not apply well to many Slavic and Yiddish surnames. Daitch-Mokotoff Soundex also includes refinements that are independent of ethnic considerations. The rules for converting surnames into D-M code numbers are listed below, followed by the coding chart.

1. Names are coded to six digits, each digit representing a sound listed in the coding chart.
2. When a name lacks enough coded sounds for six digits, use zeros to fill to six digits. GOLDEN, which has only four coded sounds (G-L-D-N), is coded 583600.
3. The letters A, E, I, O, U, J, and Y are always coded at the beginning of a name, as in Alpert (087930). In any other position they are ignored, except when two of them form a pair and the pair comes before a vowel, as in Breuer (791900) but not Freud.
4. The letter H is coded at the beginning of a name, as in Haber (579000), or preceding a vowel, as in Manheim (665600); otherwise it is not coded.
5. When adjacent sounds can combine to form a larger sound, they are given the code number of the larger sound. Mintz is not coded MIN-T-Z but MIN-TZ (664000).
6. When adjacent letters have the same code number, they are coded as one sound: TOPF is not coded TO-P-F (377000) but TO-PF (370000). Exceptions are the combinations MN and NM, whose letters are coded separately, as in Kleinman (586660, not 586600).
7. When a surname consists of more than one word, it is coded as if one word: “Ben Aron” is treated as “Benaron.”
8. Several letters and letter combinations may sound in one of two ways. The letters and combinations CH, CK, C, J, and RS are each assigned two possible code numbers.

The Daitch-Mokotoff Soundex Coding Chart

Examples of Daitch-Mokotoff Soundex Coding

For additional Daitch-Mokotoff Soundex information, see Where Once We Walked by Gary Mokotoff and Sallyann Amdur Sack (Avotaynu, 2002), pages 567–569; or Gary Mokotoff's article “Soundexing and Genealogy” on the Avotaynu website.

Adapted from the JewishGen Soundex InfoFile.