The three ways to change column width
You can change a column's width in Excel by dragging the border between column headers, by double-clicking to auto-fit the content, or by typing a specific width in the Format menu. The method you choose depends on whether you want to resize one column, multiple columns at once, or fit the width to whatever text is already in the cells.
All three methods work the same way in Excel for Windows and Excel for Mac. If you are using Excel Online (the browser version), you can only drag the column border — the other options are not available.
Key Takeaways
- Drag the border between two column headers left or right to manually widen or narrow a single column.
- Double-click the border between column headers to auto-fit the column width to the longest text in that column.
- Right-click a column header and select Format Cells to type an exact width measurement in inches or centimeters.
- Select multiple column headers at once before resizing to change the width of several columns together.
- Excel Online lets you drag column borders but does not have the Format menu options that desktop Excel offers.
Dragging the column border to resize manually
The fastest way to change one column's width is to drag. Position your cursor on the line between two column headers at the top of the spreadsheet — for example, between the A and B headers. Your cursor will change to a resize arrow (a double-headed line). Click and drag left to narrow the column or right to widen it, then release.
This method gives you full control but requires you to eyeball the width. If you need the column to be exactly a certain width, use the Format menu instead. Dragging works in Excel for Windows, Excel for Mac, and Excel Online.
Double-clicking to auto-fit column width to content
Double-click the border between two column headers, and Excel will automatically widen or narrow the column to fit the longest entry in that column. This is useful when you have text that is cut off or when you want to see all the data without manual adjustment.
If a cell contains a formula that returns a very long result, or if you have a header that is much longer than the data below it, auto-fit will size the column to whichever is longest. You can then manually adjust from there if needed. This feature works in Excel for Windows, Excel for Mac, and Excel Online.
Setting an exact column width using the Format menu
To specify a precise width, right-click on the column header you want to resize. A menu will appear. Click Column Width (in Excel for Windows) or Format Cells (in Excel for Mac), and a dialog box will open. Type the width you want in the text field. Excel measures column width in character units by default — for example, 20 means the column is wide enough to display 20 characters.
If you prefer to measure in inches or centimeters, you can change the unit in Excel's settings, but the default is character width. After you type the number, click OK. This method is the most precise and is useful when you need multiple columns to be exactly the same width.
Resizing multiple columns at the same time
Select all the columns you want to resize by clicking the first column header, then holding Shift and clicking the last column header in the range. All columns between them will be highlighted. Now drag the border of any selected column header, and all selected columns will resize together to the same width.
Alternatively, select multiple columns and then right-click to open the Format menu. Choose Column Width and type the width you want. All selected columns will be set to that exact width at once. This is faster than resizing columns one by one when you are working with a large spreadsheet.
What to do if a column is too narrow to display the data
When a column is too narrow, Excel displays ### symbols instead of the actual numbers or text. This does not mean the data is gone — it is just hidden because the column is not wide enough. Double-click the border between that column and the next to auto-fit, or drag the border to the right until the data appears.
Numbers are more likely to show as ### than text, because Excel prioritizes showing the full number value. Text will wrap to multiple lines within a cell if the column is narrow, but numbers will not wrap and will show ### instead. Widening the column is the only way to display the number.
Differences between Excel for Windows, Mac, and Online
Excel for Windows and Excel for Mac have identical column-resizing features: drag, double-click, and Format menu options all work the same way. Excel Online (the browser version you access through Office.com or Outlook) supports dragging the column border but does not have the Format menu or right-click options. If you need to set an exact width in Excel Online, you will need to use the desktop version instead.
If you are sharing a spreadsheet with others, column widths are preserved when you save and share the file, regardless of which version of Excel people use to open it. A column you widen in Excel for Windows will stay that width when someone opens the file in Excel for Mac or Online.
Frequently Asked Questions
Can I undo a column width change?
Yes. Press Ctrl+Z (Windows) or Command+Z (Mac) immediately after resizing to undo the change. If you have made other edits since resizing, undo will reverse those edits too, so undo works best right after you resize.
What does "optimal width" mean in Excel?
Optimal width is what Excel calculates when you double-click the column border. It measures the longest text or number in that column and sets the width to fit it exactly, with a small amount of padding. This is the same as the auto-fit feature.
Why does my column width keep changing when I type?
Excel Online and some versions of Excel have an auto-fit feature that activates as you type. If a cell contains text longer than the current column width, the column may widen automatically. You can turn this off in Excel settings under the Formulas tab, but it is usually not a problem in practice.
Can I set a minimum or maximum column width?
Excel does not have built-in minimum or maximum width limits. You can set a specific width using the Format menu, but there is no way to lock a column to stay within a range. If you need to prevent accidental resizing, you can protect the sheet, which disables most editing including column resizing.