Use `=SUMPRODUCT((A2:A100<>“”)/COUNTIF(A2:A100,A2:A100&””))`
Use `=SUM(–(FREQUENCY(MATCH(A2:A100,A2:A100,0),MATCH(A2:A100,A2:A100,0))>0))`
Use `=COUNTA(UNIQUE(A2:A100))` in Excel 365 or Excel 2021
Use a PivotTable and add the field to Rows, then count the listed items
Use `=SUMPRODUCT((A2:A100<>“”)/COUNTIF(A2:A100,A2:A100))` for numbers and text
Use `=SUM(–(LEN(UNIQUE(FILTER(A2:A100,A2:A100<>“”)))>0))` in newer Excel versions
Remove blanks before counting unique values if needed
Use `UNIQUE` with `FILTER` to count only distinct nonblank entries