Suppose we have a row contains some value, such as A, B, C, D, E, and a row contains some value, such as F, G, A, B, E, I. Two columns have common set: A, B, E. In Excel we can count size of common set by using a formula that combines the COUNTIF and SUMPRODUCT functions.
The general formula:
‘range1‘ and ‘range2‘ are range of cells
The result is: 3