Change the decimal separator in your spreadsheet

Excel uses the decimal separator your computer is set to — usually a period (.) in the United States, but a comma (,) in many European countries. If your spreadsheet shows commas when you want periods, or periods when you want commas, you can change this in Excel without touching your system settings. The fastest way is through Excel's Options menu, where you can set a custom decimal separator for that file alone.

This is different from formatting how numbers display — you are actually changing what character Excel recognizes as the decimal point when you type. A number typed as 3,14 will be read as 3.14 if you switch the separator, and calculations will work correctly.

Key Takeaways

  • Excel's decimal separator comes from your computer's regional settings, but you can override it in Excel's Options without changing your system.
  • The decimal separator setting in Excel applies to the current file only, so each spreadsheet can use a different separator if needed.
  • You can also use the TEXT function or number formatting to display decimals differently without changing how Excel interprets the numbers you type.
  • If you paste data from another program, the decimal separator in that data depends on what program created it, not on your Excel setting.

Change the decimal separator through Excel Options

Open the file where you want to change the decimal separator. Click File in the top-left corner, then click Options at the bottom of the menu. In the Options window, click Advanced in the left sidebar.

Scroll down to the section labeled Editing options. You will see a checkbox that says Use system separators. Uncheck this box. Two new fields will appear below it: Decimal separator and Thousands separator. In the Decimal separator field, type the character you want to use — a period (.) or a comma (,). In the Thousands separator field, type what you want to use for grouping large numbers, usually a comma or a period (whichever is not your decimal separator). Click OK to save.

The change takes effect when ready in that file. If you open a different Excel file, it will still use whatever separator was set for that file. This means you can have one spreadsheet using periods and another using commas without conflict.

Format numbers to display decimals without changing the separator

If you only want to change how decimals look on screen — not how Excel interprets them when you type — use number formatting instead. Select the cells with numbers you want to format. Right-click and choose Format Cells, or press Ctrl+1 on Windows or Command+1 on Mac.

In the Format Cells window, click the Numbers tab. On the left, click Number to see decimal options. In the Decimal places field, enter how many decimal places you want to show. Under Decimal separator, you can choose a period or comma from the dropdown. Click OK.

This method changes only the display — the actual numbers in your cells do not change, and Excel still interprets decimals the way your system is set up. This is useful when you want to show data one way but keep your typing consistent with your keyboard layout.

Use the TEXT function to display decimals in a specific format

If you need one column to show decimals with periods and another with commas, use the TEXT function. In an empty cell, type a formula like =TEXT(A1,"0.00") to display the number in cell A1 with a period and two decimal places. The formula creates a text version of the number in the format you specify.

In the TEXT function, use a period in the format code to mean "decimal separator" — Excel will automatically display it as whatever separator you chose in your regional settings or Excel options. If you want to force a specific character regardless of settings, you can type it directly: =TEXT(A1,"0,00") will display with a comma as the decimal separator.

The TEXT function is slower than formatting because it creates a new text value rather than just changing how the original number displays. Use it only when you need different formats in different parts of the same spreadsheet, or when you are combining numbers with text.

Check your system regional settings if Excel options do not work

If you uncheck Use system separators in Excel Options but the decimal separator keeps reverting, your system regional settings may be overriding it. On Windows, open Settings, click Time & language, then Language & region. Click your current language, then click Regional format settings. Look for the decimal separator setting and change it if needed.

On Mac, open System Preferences, click Language & Region, then click Advanced. You will see the decimal separator setting there. Changing your system settings affects all programs, not just Excel, so only do this if you want the change everywhere.

If you want Excel to use a different separator from the rest of your computer, keep the system setting as is and use the Excel Options method instead — that way, only Excel files are affected.

Understand how decimal separators affect data entry and formulas

When you change the decimal separator in Excel, it changes what character you must type to enter a decimal number. If your separator is set to a comma, typing 3.14 will not be recognized as a decimal — you must type 3,14. Excel will treat 3.14 as text or as a date, depending on context.

Formulas and functions work the same way. If your separator is a comma, a formula like =SUM(A1:A10) works normally, but if you manually type a number into a formula, you must use the comma: =A1+3,14 instead of =A1+3.14. This can be confusing if you are used to typing periods, so many people keep their Excel separator matched to their keyboard layout.

Data pasted from other programs brings its own decimal separator — if you paste a list of numbers that use periods into a spreadsheet set to commas, those numbers may not calculate correctly until you convert them. Use Find & Replace (Ctrl+H on Windows, Command+H on Mac) to swap all periods for commas, or vice versa, if this happens.

Frequently Asked Questions

Will changing the decimal separator in Excel affect my other programs?

No. If you change it through Excel Options, only that Excel file is affected. If you change your system regional settings, all programs on your computer will use the new separator. To avoid affecting other programs, use the Excel Options method instead.

Can I have different decimal separators in different sheets of the same file?

No. The decimal separator setting applies to the entire file, so all sheets in that workbook use the same separator. If you need different separators, use the TEXT function to format specific cells, or save different sheets as separate files.

What happens to my formulas if I change the decimal separator?

Existing formulas continue to work because Excel updates them automatically. However, if you type new formulas after changing the separator, you must use the new separator when typing numbers. For example, if you switch to commas, type =A1+5,5 instead of =A1+5.5.

How do I change the decimal separator back to the default?

Go back to File > Options > Advanced, and check the box next to Use system separators. Excel will return to using whatever decimal separator your computer is set to. If you want to change your system default, adjust your regional settings in Windows or Mac preferences.

Why does my data show periods when I set the separator to commas?

The data may have been entered or pasted before you changed the separator, or it may be formatted as text. Select the cells and use Find & Replace to swap periods for commas, then re-enter the cells so Excel recognizes them as numbers. You can also copy the cells, use Paste Special with the Add operation to force recalculation.