Whenever you want to multiply several values in Excel and then aggregate the results, the SUMPRODUCT function is ideal. For example, if you have several matrices in your worksheet and you want to add them together, it’s very easy to do so with SUMPRODUCT. Let’s assume we have a table with two columns: SUMPRODUCT lets you multiply the two values in each row with one another and then sum them.
SUMPRODUCT is a matrix formula. Typically, if you want to use a function as a matrix formula, you have to confirm entry of the formula using the keyboard shortcut [Ctrl] + [Shift] + [Enter]. But you don’t have to do that with SUMPRODUCT because the function is designed for processing matrices. That is why Excel doesn’t require a special command.