Excel Text Underline Shortcut: Windows, Mac, and Web

In Excel for Windows, select the cell or text you want to underline and press Ctrl+U. On a Mac, use Command+U; the shortcut toggles underline on or off for the current selection.

What the Excel underline shortcut does

Ctrl+U is a formatting shortcut, not a command that inserts an underline character. It applies the underline font style to the selected cell or selected characters. Pressing the shortcut again removes that style from the selection, so it is useful for quickly switching between underlined and regular text.

What gets formatted depends on what is selected when you use the shortcut:

One selected cell: Excel underlines the cell’s contents. The cell’s font formatting also applies to content entered there later, unless you change the formatting.
Several selected cells: Excel applies underline formatting to the selected cells.
Characters selected while editing a cell: Excel can underline just those characters, leaving the rest of the cell’s text unchanged.

The shortcut changes the appearance of the text; it does not add a bottom border to the cell. That distinction matters in tables and reports, where a line beneath a cell and an underline beneath its characters can look similar but behave differently.

How to underline a cell or range

To underline the contents of one or more cells in Excel for Microsoft 365 on Windows:

Select a cell, a group of cells, or a range on the worksheet.
Press Ctrl+U.
Check that the text in the selected cells is underlined. Press Ctrl+U again if you want to remove the underline.

You can select a range by dragging across cells or by clicking the first cell and then Shift-clicking the last one. To select nonadjacent cells, hold Ctrl while selecting them, then apply the shortcut. Be mindful of the selection: if a whole range is active, the formatting applies to the whole range, not just the cell where the pointer happens to be.

For example, if a worksheet has column headings in B2:E2, select B2:E2 and press Ctrl+U to underline all four headings. The values remain unchanged; only their font formatting changes. If you intended to underline just the word “Total” within a cell, edit the cell and select that word instead of selecting the entire cell.

Underline only part of a cell’s text

Excel supports character-level formatting for text stored directly in a cell. To format only a word or phrase, enter editing mode, select the characters, and apply the underline shortcut:

Double-click the cell, or select it and press F2, to edit its contents.
Select the characters you want to underline. You can also click in the formula bar and select the relevant text there.
Press Ctrl+U on Windows or Command+U on Mac.
Press Enter to finish editing and check the result.

For instance, suppose a cell contains “Read the instructions before submitting.” You can select “instructions” while editing and underline only that word. If selecting the characters is difficult, enlarge the formula bar by dragging its lower edge, or use the cell’s edit mode so there is more room to work.

There is an important limitation: a formula result is not ordinary editable text for character-level formatting. You can underline the formula cell as a whole, but you cannot use the keyboard to select and underline only a few characters produced by a formula. If partial formatting is essential, consider placing the words in a text-entry cell or redesigning the presentation.

Single underline, double underline, and borders

The standard Ctrl+U shortcut applies or removes a single underline. Excel also offers a double underline style, which is often used for financial totals. To choose it, open the underline menu from Home > Font > Underline using the menu arrow beside the Underline button, then choose the double underline option. The exact appearance can vary with the font and zoom level.

A cell border is a separate formatting feature. Use a bottom border when the goal is to draw a line across the width of a cell or range, including blank space; use font underline when the line should sit beneath the characters themselves. For a report total, a bottom border may form a cleaner visual divider, while underlining the label or amount emphasizes the text itself.

In other words, a line that appears beneath a value is not automatically an underline. If Ctrl+U does not produce the full-width line you expected, you may need a border instead. Borders are available from the Borders menu in the Home tab’s Font group.

Use the ribbon or Format Cells instead

If you forget the shortcut, or prefer to see the formatting choice before applying it, use the ribbon. Select the target cell or text, then go to Home > Font > Underline. Click the Underline button for a single underline, or open its arrow menu to choose another available underline style.

The Format Cells dialog offers another route and can be useful when adjusting several font properties together. Select the cells and press Ctrl+1 on Windows to open Format Cells, then choose the Font tab and set the Underline option. On Mac, use Command+1 to open Format Cells in supported Excel versions; if that shortcut is unavailable in your setup, use the ribbon’s Format Cells options. Confirm with OK to apply the change.

The ribbon and dialog are especially useful when a keyboard shortcut is intercepted, when you need double underline, or when you are checking whether underline is currently part of a cell’s font formatting. They also make the distinction between font effects and borders easier to see.

Windows, Mac, and Excel for the web

For Excel for Microsoft 365 on Windows, the direct shortcut is Ctrl+U. In Excel for Mac, the equivalent is Command+U. The modifier key differs because Mac applications generally use Command for many common editing and formatting shortcuts.

Excel for the web also provides keyboard shortcuts for formatting, but browser behavior and keyboard settings can affect which shortcuts are available. With the workbook active, try Ctrl+U on Windows or Command+U on Mac. If the browser handles the keystroke instead, use the ribbon’s Underline button. This is a practical fallback when a shortcut behaves differently in a browser than in the desktop app.

These instructions concern Excel, not every spreadsheet program. A shortcut that looks familiar in another application may perform a different action there, so check the application name and whether the workbook has focus before troubleshooting Excel formatting.

Common reasons Ctrl+U seems not to work

If the text does not appear underlined, first check the selection and the active window. A shortcut only affects the active workbook when Excel has focus, and a cell selection is different from a selection of characters inside a cell.

The wrong cells are selected: Click the intended cell or select the correct range, then try again.
You are editing the wrong text: To underline only part of a cell, enter edit mode and select the characters before pressing the shortcut.
You expected a border: Ctrl+U formats the font. Apply a bottom border if you need a line spanning the cell.
The font style is difficult to see: Check the text color, font size, zoom level, and cell background. The formatting may be applied but visually subtle.
A browser or keyboard setup captures the shortcut: Use Home > Font > Underline instead.
The cell contains a formula: You can underline the displayed result as a whole, but not select only a portion of the formula’s returned text for character-level formatting.

To confirm the setting, select the cell and look at the Underline button on the Home tab. You can also open Format Cells and inspect the Font tab. If the button looks active but no line is obvious, try a larger font or a contrasting text color before concluding that the shortcut failed.

When to underline—and when not to

Underlining can help identify a heading, emphasize a short label, or distinguish a total in a compact worksheet. It is most effective when used consistently and sparingly. Underlining many adjacent values can make a dense table harder to scan, particularly when the underline sits close to descenders such as the letters g, p, and y.

For headings, bold text, a fill color, or a bottom border may provide clearer hierarchy. For an important value, consider whether a number format, color, or border communicates its role better. Also avoid using underline as the sole signal that something is important: readers may associate it with a hyperlink, and people using assistive technology may benefit from additional labels or visual cues.

These choices are about presentation rather than calculation. Applying or removing underline does not change a number’s value, a formula’s result, or how Excel sorts and calculates the cell. It changes the cell’s visual formatting, which can still matter for readability and for a consistent, accessible workbook design.

Frequently Asked Questions

What is the shortcut to underline text in Excel?
In Excel for Windows, press Ctrl+U. On a Mac, press Command+U. Select the cell or text first; the shortcut toggles underline formatting for that selection.

How do I remove an underline in Excel?
Select the underlined cell or characters and press Ctrl+U on Windows or Command+U on Mac again. You can also click the Underline button on the Home tab to turn the formatting off.

Can I underline just one word in an Excel cell?
Yes, if the cell contains directly entered text. Edit the cell, select the word, and use the underline shortcut. A formula result can be underlined as a whole, but not selectively formatted character by character in this way.

How do I apply a double underline in Excel?
Open the arrow menu beside the Underline button at Home > Font > Underline and choose the double underline style. Ctrl+U by itself applies the standard single underline.

Does Ctrl+U create a line under the whole cell?
No. It underlines the text characters. To draw a line across the bottom of a cell or range, use a bottom border from the Borders menu in the Home tab’s Font group.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

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