The guide · SUM
What SUM does
SUM adds numbers. You can give it single cells, whole ranges, or a mix: =SUM(B2:B6) adds every cell from B2 down to B6, and =SUM(B2:B6, D2) adds one more cell on top. Because the formula points at cells instead of copying their values, the total updates the moment one of those numbers changes. That is the whole reason to use a formula instead of a calculator.
Syntax
=SUM(number1, [number2], …)Each argument can be a number, a cell like B2, or a range like B2:B6. A range is written as the first cell, a colon, and the last cell.
The fastest way to write it
- Click the cell where the total should go.
- Type
=SUM( - Drag across the cells you want to add. Excel writes the range for you.
- Press Enter. Excel closes the bracket if you forget it.
In real Excel, Alt+= (Windows) or ⌘+Shift+T (Mac) inserts a SUM of the cells above in one keystroke.
Common mistakes
- Typing the answer instead of a formula. If you type
1420, it looks right today and is wrong as soon as the rent changes. Always start with=. - Leaving a row out.
=SUM(B2:B5)silently skips B6. Check the colored border around your range before pressing Enter. - Including the total cell itself.
=SUM(B2:B7)written in B7 refers to its own cell and causes a circular reference. - Numbers stored as text. SUM skips text inside a range, so a value imported as
"950"won't be counted.
FAQ
- How do I sum a column in Excel?
- Click the cell below the column, type =SUM( and drag over the numbers, then press Enter. For example =SUM(B2:B6) adds B2, B3, B4, B5 and B6.
- Why does my SUM formula return 0?
- Usually the numbers are stored as text, for example after an import. SUM ignores text in ranges. Convert them to numbers and the total appears.