The simplest way to add numbers in Excel

To add numbers in Excel, you type a formula that starts with an equals sign, followed by the word SUM, then the cells you want to add. For example, if you have numbers in cells A1, A2, and A3, you type =SUM(A1:A3) and press Enter. Excel then shows you the total.

The colon between A1 and A3 tells Excel to add everything in that range — all the cells from A1 through A3. If your numbers are scattered and not next to each other, you can list each cell separately: =SUM(A1,A3,A5) adds only those three cells and skips A2 and A4.

You can also add just two cells by typing =A1+A2, but SUM is faster when you have many numbers because you do not have to type a plus sign between each one.

Key Takeaways

  • Type =SUM(A1:A3) to add a range of cells, where the colon means "through" — this adds every cell from A1 to A3.
  • Type =SUM(A1,A3,A5) to add only specific cells that are not next to each other.
  • Press Enter after you type the formula, and Excel shows the total in that cell.
  • You can copy a formula down to other rows by clicking the cell with the formula and dragging the small square at the bottom-right corner downward.
  • Excel updates the total automatically if you change any of the numbers in the cells you are adding.

Where to type the formula

Click on the cell where you want the total to appear. This is usually below or to the right of the numbers you are adding. Then type your formula directly into that cell. You will see the formula appear both in the cell and in the formula bar at the top of the screen.

Do not click on the cells you want to add first — just click on the empty cell where you want the answer, then type the formula. Excel will understand which cells you mean from the cell references in your formula.

Adding a column of numbers

If you have a column of numbers running down the page, click on the empty cell right below the last number. Type =SUM(A1:A10) if your numbers are in cells A1 through A10. You can also click on the first cell with a number, hold Shift, and click on the last cell with a number — Excel will show you the range in the formula bar, and you can copy that range into your SUM formula.

A faster method: click on the empty cell below your numbers and look for the AutoSum button in the toolbar at the top. It looks like the Greek letter sigma (Σ). Click it, and Excel guesses which cells you want to add and fills in the formula for you. If the guess is wrong, you can edit the formula before pressing Enter.

Adding numbers across a row

If your numbers run left to right across the page instead of up and down, the process is the same. Click on the empty cell to the right of your last number and type =SUM(A1:E1) if your numbers are in cells A1 through E1 on the same row. The colon still means "through," so this adds all cells from A1 to E1.

You can also use the AutoSum button the same way — click the empty cell to the right, click AutoSum, and let Excel fill in the formula.

Copying a formula to multiple rows or columns

Once you have written a SUM formula in one cell, you can copy it to other cells and Excel will adjust the cell references automatically. For example, if you have a formula =SUM(A1:A10) in cell B1, and you copy it down to cell B2, Excel changes it to =SUM(A2:A11) — it shifts the range down by one row.

To copy a formula down: click on the cell with the formula, then look for the small square at the bottom-right corner of the cell. Click and drag that square downward as far as you need. Excel copies the formula to each row and adjusts the cell references. You can also copy the cell (Ctrl+C on Windows, Command+C on Mac), select the range where you want it, and paste (Ctrl+V or Command+V).

When your numbers change

If you edit one of the numbers in a cell that your formula uses, Excel recalculates the total automatically. You do not have to rewrite the formula or press Enter again — the total updates as soon as you finish editing that cell.

This is one reason SUM formulas are more useful than a calculator. If you realize you entered a number wrong, you just fix it in the cell, and all your totals update when ready. If you had used a calculator and written down the answer by hand, you would have to recalculate everything.

Adding numbers with conditions

Sometimes you want to add only the numbers that meet a certain condition — for example, add only the sales over $500, or add only the entries from January. For this, you use SUMIF instead of SUM. The formula looks like =SUMIF(A1:A10,">500"), which adds only the numbers in cells A1 through A10 that are greater than 500.

SUMIF takes three parts: the range of cells to check, the condition in quotes, and optionally a different range to add. For example, =SUMIF(B1:B10,"January",C1:C10) checks column B for the word "January" and adds the matching numbers from column C. This is useful when you have a spreadsheet with dates or categories and you want to total only certain rows.

Frequently Asked Questions

What if I type a formula and see an error instead of a number?

The most common error is #NAME?, which means Excel does not recognize the formula. Check that you typed SUM correctly and that your cell references use letters and numbers (A1, not A-1). Another common error is #REF!, which means the formula refers to a cell that no longer exists — this happens if you delete a column or row that the formula used. Delete the formula and rewrite it using the correct cells.

Can I add cells from different sheets in the same workbook?

Yes. Type =SUM(Sheet1.A1:A10,Sheet2.A1:A10) to add a range from Sheet1 and a range from Sheet2. The period separates the sheet name from the cell reference. If your sheet name has a space, put it in single quotes: =SUM('Sheet 1'.A1:A10).

How do I add only the visible cells if I have hidden some rows?

Use SUBTOTAL instead of SUM. Type =SUBTOTAL(9,A1:A10), where 9 is the code for sum. SUBTOTAL ignores hidden rows, so if you filter your data and hide some rows, SUBTOTAL adds only what you see. SUM would add the hidden rows too.

What if I want to add numbers but also subtract others in the same formula?

You can combine operations: =SUM(A1:A5)-SUM(B1:B5) adds all of A1 through A5, then subtracts all of B1 through B5. You can also type =A1+A2-B1-B2 if you have just a few cells. Excel follows the normal order of operations, so multiplication and division happen before addition and subtraction.