How to Add Single and Double Underlines to Excel Cell Text

You may need to format text in Excel with underlines for emphasis or to follow specific style guides. Excel provides distinct single and double underline options for cell text. This article explains how to apply both underline types using the ribbon and keyboard shortcuts.

Excel’s Underline Formatting Options

Excel offers two primary underline styles for cell content. The standard single underline is commonly used for emphasis. The double underline is often used in accounting and financial statements to indicate a final total. These formats are part of the cell’s font properties and apply to all characters within the selected cell or range.

You must select the cell or specific text within a cell before applying an underline. The formatting affects the entire cell content by default. If you double-click into a cell, you can select only a portion of the text to underline. The underline will appear directly beneath the text, not across the entire cell width unless the cell is full.

Steps to Apply Single and Double Underlines

You can add underlines using the ribbon commands or the Format Cells dialog. The ribbon provides quick access, while the dialog offers the complete set of underline styles.

Method 1: Using the Home Tab Ribbon

1. Select the target cells
   Click on the cell you want to format. To format multiple cells, click and drag to select a range.
2. Apply a single underline
   Go to the Home tab on the ribbon. In the Font group, click the Underline button, which shows a single underlined ‘U’. This applies a single underline.
3. Apply a double underline
   Click the small arrow in the bottom-right corner of the Font group. This opens the Format Cells dialog. Click the Font tab. Click the Underline style dropdown menu and select ‘Double’. Click OK to apply.

Method 2: Using Keyboard Shortcuts

1. Select the cells
   Use the arrow keys or mouse to select the cell or range to format.
2. Use the shortcut for single underline
   Press Ctrl+U on your keyboard. This toggles the standard single underline on the selection. Press Ctrl+U again to remove it.
3. Open the Format Cells dialog
   Press Ctrl+1 to open the Format Cells dialog directly. Navigate to the Font tab, select ‘Double’ from the Underline style dropdown, and press Enter.

Common Formatting Mistakes and Limitations

Underline Does Not Extend Across Empty Cell Space

The underline only appears under the text characters. If your cell contains a short word, the underline will be short. To create a line that fills the cell, use the border feature instead. Select the cell, go to Home > Font group > Borders button, and choose a bottom border.

Double Underline Not Available on the Main Ribbon Button

The main Underline button on the Home tab only applies a single underline. You cannot access the double underline style from that button alone. You must use the Font dialog launcher or the Ctrl+1 shortcut to find the double underline option.

Underline Color Matches Text Color

The underline color automatically matches the font color of the cell text. You cannot set the underline to a different color independently using standard font formatting. To have a differently colored line, you would need to use a bottom cell border.

Single vs Double Underline: Key Differences

Item	Single Underline	Double Underline
Primary Use	General text emphasis	Denoting a grand total in accounting
Ribbon Access	Direct button on Home tab	Requires Format Cells dialog
Keyboard Shortcut	Ctrl+U (toggle)	No direct shortcut
Visual Weight	Standard line weight	Two parallel lines for stronger emphasis

You can now format your Excel data with precise underline styles. Use the Ctrl+U shortcut for quick single underlines during data entry. For financial reports, remember the double underline is in the Format Cells dialog under the Font tab. An advanced tip is to create a cell style with a double underline preset for consistent formatting across workbooks.