In <1162498243.042396.267400@m73g2000cwd.googlegroups.com>,

TKnTexas said:

I am entering data to column B, a 5-digit number. Is there a

formula that I can put in column D that will tell me if the

number is a duplicate.

Supposing your data starts in Row 2, and supposing your

data ends in Row 2000, then in D2 and dragged down could

go:

=COUNTIF($B$2:$B$2000,$B2)

Here's a sample:

B C D

----- --- ---

12345 1

12346 1

12347 1

12348 1

12349 1

12350 1

12351 1

12352 1

12353 2 <------

12353 2 <------

12355 1

You could also, or alternatively, use Conditional Formatting

(Format -> Conditional Formatting) to bring dupes to your

attention. The conditional formula could be, e.g.:

=COUNTIF($B$2:$B$2000,$B2)-1

-dman-