How can I count duplicate data in a column using excel?
Example
A B
apple 1
apple 2
apple 3
ball 1
bat 1
dog 1
do
I think there is no uniform formula for all cells in your case.
I would suggest something like this: Put this on B column and then fill down the rest.
=COUNTIF($A$1:$A1,$A1)
After you fill the other rows, values of rows would look like this
B1=COUNTIF($A$1:$A1,$A1)
B2=COUNTIF($A$1:$A2,$A2)
B3=COUNTIF($A$1:$A3,$A3)