What is the SUM Function
The SUM function adds all the numbers in a range of cells. It is the most used formula in Excel and the foundation of almost every calculation. SUM ignores text and blank cells automatically.
Formula: =SUM(number1, [number2], ...)
Practical Example 1
Monthly sales are in B2 to B6.
Type: =SUM(B2:B6)
Result: 1200 (the total of all five values)
Practical Example 2
Add multiple non-adjacent ranges.
Type: =SUM(B2:B6, D2:D6)
Result: the combined total of both ranges
Practical Example 3
Add an entire column.
Type: =SUM(A:A)
Result: the total of column A
Practical Example 4
Add up to a certain point using SUM and a range.
Type: =SUM(A2:A10)
Result: the total of A2 to A10
When to Use It
SUM is used for adding total sales, for summing expenses, for calculating totals across rows or columns, for financial reports, and for any situation where you need a total.