Why Excel SUM is zero.
Why Excel Sum function not working.
Why Excel SUM returns 0.
Why Excel Sum is wrong.
Why Excel Sum shows 0.
Why Excel Not Showing Sum.
Why Excel Sum Formula Not working.

Do you have a column of numbers that won’t sum in Excel? It is most likely that the numbers have been stored as text. Here are two quick ways to convert those text numbers and the numbers will then sum.

One frustrating behavior when this happens: =SUM(A2:A4) is zero, but =A2+A3+A4 calculates correctly. That is because the plus sign coerces a number out of the text, but the SUM function is programmed to ignore text.