Intro to Excel: cells, formulas and SUM
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An Excel formula starts with = and calculates a result from other cells. For example, =B2*C2 multiplies the quantity in B2 by the price in C2, and =SUM(D2:D6) adds up a column. When the data changes, the result updates by itself.
How a formula is built
=B2*C2
- =
- Tells Excel that what follows is a calculation, not text. Without it, Excel just shows what you typed.
- B2
- A cell reference: column B, row 2. Excel uses the value currently in that cell.
- + - * /
- Operators: add, subtract, multiply, divide. Use brackets to calculate a part first, e.g.
=(B2+B3)*C2. - SUM(D2:D6)
- A function with a range.
D2:D6means every cell from D2 to D6.
Practise the basics
Five short guided steps, from clicking a cell to adding up a range. No sign-up needed.
Cells and references
In Excel, each rectangle is a cell. Columns are labelled with letters and rows with numbers, so the cell in column A and row 3 is called A3. That name is its cell reference. Click cell B2 to continue.
How to write a formula
- Click the cell where you want the result.
- Type
=, then click the first cell you need. Excel writes its reference for you. - Type an operator such as
*, then click the next cell. - Press Enter. Select the cell again to see the formula in the formula bar.
Examples
Line total
=B2*C2
Quantity times unit price.
Total of a column
=SUM(D2:D6)
Adds every number from D2 to D6.
Average
=AVERAGE(B2:B7)
Adds the numbers and divides by how many there are.
Rounded average
=ROUND(AVERAGE(B2:B7),1)
One function inside another: the average, rounded to 1 decimal place.
Common errors
| Error | Cause | Fix |
|---|---|---|
| #NAME? | A function name is misspelled, or it’s written in another language than your Excel. | Check the spelling. In French Excel SUM is SOMME, in German SUMME. |
| #VALUE! | The formula does maths on text, such as a header cell. | Make sure the references point to cells that contain numbers. |
| #DIV/0! | The formula divides by zero or by an empty cell. | Check the cell you divide by. |
| ##### | The column is too narrow to show the number. | Widen the column. The value itself is fine. |
Formula or typed value?
Typing 30 in D2 and writing =B2*C2 can show the same number, but only the formula stays right when the quantity or the price changes. That’s why every exercise here asks for a formula, not a typed result.
Questions
Do I need Excel installed to practise?
No. The sheet on this page calculates like Excel in your browser. What you learn works the same in Excel, Excel for the web and most other spreadsheets.
Why does my Excel use ; instead of ,?
Excel follows the language and region settings of your computer. In French, German, Portuguese and Spanish Excel, arguments are usually separated by ; because the comma is the decimal separator.