Some Excel formulas combine multiple functions into one. These are called compound functions. For example, SUMIF blends SUM and IF to total values that meet specific criteria, though it doesn’t behave exactly like using SUM and IF separately.

It's important to note that the criterion applies to the evaluated cells, not the sum itself. This can be confusing. It's easy to assume that if the criterion isn't met, nothing will be summed.

You can break this function into its components and analyze the steps it takes to understand how it works. Let's start with an IF formula.

You can then use the SUM formula on C1:C6 to get the same result—but SUMIF is more convenient since it does everything in one step. It's also less error-prone, as you don't need to handle the if_false case like you would with IF.