Countif avoiding duplicates

[mikmonto]

Hi all,

I have this situation:

A 1
A 2
A 2
B 1
B 2

And I want to group data based on 2nd column (the one with 1s and 2s), not double counting the values in 1st column.
To be clear, the desired outcome should be:
1 -> 2
2 -> 2

How can I solve this?

Thanks,
M

[Fotis1991]

http://stackoverflow.com/questions/1...alues-in-excel

[Richard Buttrey]

Hi,

Please clarify.

I can indeed see two unique letters (A & B) based on number 1s, i.e. A1 & A4
But I can only see two unique letters (A & B) based on number 2s, i.e. A2 (or A3) & A5.

Where do you get 3 unique letters fro number 2?

[mikmonto]

My mistake Richard. Indeed I edited it straight after. It's 2 and 2