Soundex and sound-alike surnames
Census indexes and many immigration databases file surnames by their Soundex code, so a name spelled three ways sits in one place. Type a surname to get its code and every US surname that shares it.
How Soundex works
- Keep the first letter.
- Replace the rest with digits: B, F, P, V = 1; C, G, J, K, Q, S, X, Z = 2; D, T = 3; L = 4; M, N = 5; R = 6. Vowels, H, W and Y are dropped.
- Letters with the same digit next to each other count once, also when only H or W separates them.
- Pad with zeros or cut to one letter and three digits: Robert and Rupert are both R163.
Surname list: every name held by 100 or more people in the 2010 US Census.