How to Write Your First Excel Formula

Here is how to write a formula in Excel: click a cell, type =, point at the cells you want to use, add a math sign such as *, and press Enter. That's all a formula is. This guide walks you through your first one step by step, then shows you SUM and the mistakes beginners make most. You don't need any Excel experience to follow it.

What is a formula in Excel?#

A formula is an instruction that tells Excel to calculate something, and it always starts with an equals sign (=). Anything you type into a cell is either a value or a formula:

• A value is text or a number, like Lena or 25. Excel shows it exactly as you typed it.
• A formula starts with =, like =C2*D2. Excel shows the result in the cell.

When you click a cell with a formula, the formula bar (the long box above the grid) shows the formula itself. That is how you check what a cell is really doing.

How to write a formula in Excel, step by step#

Let's work out pay from hours and an hourly rate. Type this small table into a new sheet:

Priya's pay is her hours times her rate:

1. Click E2, the cell where the answer should go.
2. Type =.
3. Click C2. Excel adds C2 to the formula.
4. Type * (Shift+8). This is Excel's multiply sign.
5. Click D2.
6. Press Enter.

E2 now shows 1440, and the formula bar shows =C2*D2. In E4, Lena's pay is =C4*D4, which gives 750.

Excel's math signs#

Excel uses these signs (called operators) in formulas:

Excel does * and / before + and -, so =2+3*4 gives 14, not 20. Parentheses change the order: =(2+3)*4 gives 20. The full rules are in the Excel order of operations.

Why you should point at cells, not type numbers#

A formula that uses cells updates by itself. =C2*D2 and =32*45 both show 1440 today. But if Priya's hours change to 36, only =C2*D2 updates, to 1620. The typed version stays at 1440 and is now wrong.

So point at cells whenever the number is already in the sheet. The cell names, like C2, are called cell references. Excel cell references explained covers them in more detail.

How to add up a column with SUM#

SUM is a function: a ready-made calculation with a name. You type =, the name, then the cells to use inside parentheses.

In B6, type =SUM(B2:B5) and press Enter. The result is 220600. B2:B5 is a range: every cell from B2 to B5. It adds the same cells as =B2+B3+B4+B5, with much less typing.

A comma lists single cells instead: =SUM(B2,B5) adds only Q1 and Q4, which gives 106900.

AutoSum writes the SUM for you. Click the cell under the numbers and press Alt+= on Windows or ⌘⇧T on a Mac, check the range Excel picked, then press Enter. See the SUM function guide for more examples, or the SUM function in Excel for a full walkthrough.

How to check and change a formula#

To see a formula, click its cell and read the formula bar. The cell itself only shows the result, so the formula bar is where you check what Excel is really calculating.

To change a formula, select the cell and press F2 (⌃U on a Mac), or double-click it. The cursor appears at the end, and each cell reference is shown in its own colour, with a box of the same colour around the cell on the sheet. Fix the part that's wrong and press Enter. Press Esc instead to leave the formula as it was. Editing cells without the mouse has more keys for fixing mistakes.

How to copy your formula to the other rows#

You don't need to write the same formula again for every row. Select E2:E4 and press Ctrl+D (⌘D on a Mac). Excel copies the formula down, and each copy uses its own row: E3 becomes =C3*D3. Fill Down and Fill Right explains how this works.

Sometimes you need one cell to stay fixed while the others move, such as a tax rate. That needs a dollar sign. See how to copy a formula without changing its references.

Common first-formula mistakes#

These are the problems almost every beginner hits:

• No equals sign. C2*D2 is just text. Add = at the start.
• The formula shows instead of the result. The cell was formatted as Text before you typed. Change it to General (Ctrl+Shift+, or ⌃⇧ on a Mac), then edit the cell and press Enter.
• Using x to multiply. =C2xD2 doesn't work. Use *.
• #NAME? Excel doesn't know a name you typed. Check the spelling: =SUMM(B2:B5) should be =SUM(B2:B5).
• #DIV/0! You divided by zero or by an empty cell.
• #VALUE! You did math with text, for example a cell that says "n/a".
• ####. The result is fine; the column is too narrow. Make the column wider.

Practise your first formulas#

The fastest way to learn is to type formulas yourself and see them work. Open the your first formulas lesson to write =C2*D2, watch it recalculate and use parentheses. Then try the SUM and AutoSum lesson to total a column. Formulas like these are everyday work in Excel for admin jobs, and how long it takes to learn Excel shows what to learn next.