How to Write a Basic Formula in Excel
Everything starts with the equals sign — from there, SUM, AVERAGE, MAX and MIN cover most everyday needs, and the fill handle copies a formula down a whole column in one drag.
The fundamental rule: every formula starts with "="
Without the equals sign at the start, Excel treats what you type as ordinary text, not as a formula to calculate.
A basic sum
=A1+A2
Adds the contents of cells A1 and A2.
The SUM function (for many cells)
=SUM(A1:A10)
Adds the whole range from A1 to A10 — far more practical than chaining "+" cell by cell when there are many.
Other useful basic functions
| Function | What it does |
|---|---|
=AVERAGE(A1:A10) | Calculates the mean of the range |
=MAX(A1:A10) | The highest value in the range |
=MIN(A1:A10) | The lowest value in the range |
=COUNT(A1:A10) | How many cells in the range contain numbers |
Tip: use Alt + = to AutoSum the selected column or row instantly, without typing the formula by hand.
Copying a formula to other cells
Select the cell with the formula → drag from the bottom-right corner (the small square) downward or sideways — Excel automatically adjusts the cell references for each new position.
Frequently asked questions
Why does my formula show as text instead of calculating?
Check that it starts with the equals sign (=) — without it, Excel treats the content as ordinary text instead of interpreting it as a formula to calculate.
How do I apply the same formula to many cells quickly?
Drag from the bottom-right corner of the cell containing the formula to wherever you need it — Excel automatically adjusts the references for each new position.