=RIGHT(SUBSTITUTE(A1,".","~",LEN(A1)-LEN(SUBSTITUTE(A1,".",""))),LEN(SUBSTITUTE(A1,".", "~",LEN(A1)-LEN(SUBSTITUTE(A1,".",""))))-FIND("~",SUBSTITUTE(A1,".","~",LEN(A1)-LEN(SUBSTITUTE(A1,".","")))))

--
Kind regards,

Niek Otten
Microsoft MVP - Excel

"garle" wrote in message oups.com...
| Given file names that appear in a worksheet, and contain extensions of
| uncertain length (e.g. .txt, .properties, .doc, etc), what's a good
| formula to return the extension string itself?
|
| Would want this to fail gracefully if there is no extension and handle
| cases where "." appears elsewhere in the file name. That is, return the
| last string delimited by "."
|
| Thanks in advance!
|