Counta unique string on filtered list

Question

I'd like to count unique string values on a filtered list (For example, the value should be 3 in this screenshot):

How can this be done in google sheets?

Here's the spreadsheet: https://docs.google.com/spreadsheets/d/1O1rZUstDNSXPdUVXvaDfPO4rAQs2cJWHimfGxbddtNU/edit#gid=0

Answer 1

• you will need a helper column with SUBTOTAL to evaluate hidden rows
• expand/cancel your filter

• paste this in C3 cell and drag down:

  =SUBTOTAL(103, B3)

• then paste this into B1 cell:

  =COUNTA(IFERROR(UNIQUE(FILTER(B3:B, C3:C=1))))

  

Answer 2

Use UNIQUE to get a list of unique values then COUNTA to count those values. You could even nest them:

=COUNTA(UNIQUE(B3:B))