Underline Text Calculator - HTML, CSS & Markdown Output

The underline text calculator turns any short phrase into a ready-to-paste underlined string in the markup format you choose. It is a small text-formatting helper for social posts, blog drafts, wiki pages, classroom handouts, forum threads, and source code comments, where the underline needs to travel with the text instead of relying on a custom font.

• • Forum and chat messages: Wrap a word in BBCode, HTML, or Markdown so it shows underlined in Discord, Reddit, phpBB, and most forum engines without changing your keyboard layout.
• • Source code and documentation: Drop a LaTeX \underline snippet into a paper, a Markdown __word__ into a README, or a CSS span into a stylesheet for code samples that need a visible underline.
• • Plain text and email subject lines: Use the Unicode combining low line or the ASCII underscore row when the destination strips markup, including older email clients, social bios, and SMS messages.
• • Lesson plans and study notes: Highlight vocabulary in handouts by pasting underlined words from the calculator into a worksheet or shared document, then use the character counts to fit page budgets.

The result is a copy-ready string, not a styled image, so paste the underlined output into almost any text field and the underline travels with the characters.

For longer documents where the same format repeats, count words up front with a Word Count Calculator so you can plan a worksheet or social caption before pasting the underlined lines in.

The calculator reads your text, applies the markup rules for the selected output format, and reports the resulting string along with the source character count and the output string length.

• text: The plain-text string entered in the textarea, truncated to 5,000 characters before processing.
• format: The selected output convention: HTML, CSS, Markdown, BBCode, LaTeX, Unicode combining, or ASCII.
• includeSpaces: A yes-or-no setting used only by the Unicode format; it controls whether the U+0332 mark is added after space characters.

The HTML and CSS branches escape ampersands, angle brackets, and quotes so the output can be pasted into another document without breaking the surrounding markup.

For the Unicode combining format, each character is paired with the U+0332 mark, which the receiving font renders as a line beneath the preceding base character.

According to MDN Web Docs, the <u> HTML element represents text with an unarticulated, though explicitly rendered, non-textual annotation such as underlining the text.

According to MDN Web Docs, the text-decoration CSS shorthand property sets the appearance of decorative lines on text, including the common underline value.

When the underlined phrase is part of a longer student draft, the Essay Word Count & Reading Time Estimator shows how the surrounding paragraph fits the target essay length.

Knowing which markup fits which destination helps you choose the right format the first time.

When the destination platform is a phone keypad, a social bio, or a chat that strips markup, fall back to the Unicode or ASCII outputs from this calculator.

If you need a single plain-text character turned into a styled Unicode symbol rather than an underline, the Unicode Text Calculator covers related styles such as circled, squared, monospace, fullwidth, and upside-down text for the same string.

Five short steps cover every common workflow, from a quick BBCode post to a Pandoc manuscript.

1. 1 Type the source text: Enter the word, phrase, or sentence to underline in the textarea. Long inputs are accepted up to 5,000 characters.
2. 2 Choose a destination format: Select HTML, CSS, Markdown, BBCode, LaTeX, Unicode, or ASCII based on where you plan to paste the result.
3. 3 Adjust the Unicode option when relevant: For Unicode, set include-spaces to yes to underline every character or no to leave space characters plain.
4. 4 Copy the generated output: Read the underlined text in the result panel and copy it into your editor, message, post, or stylesheet.
5. 5 Check the character counts: Use the input code-point count and the output length to fit destination limits such as social character caps or email subject lines.

A student enters the word "Review", picks Markdown, and the calculator returns __Review__. Pasting that into a Pandoc-built PDF renders the word with an underline, and the output length field shows 9 characters, which fits the column width they planned for the worksheet.

When a worksheet, lesson plan, or slide deck also needs the binary form of the same phrase, the Text to Binary Converter sits next to this calculator and shares the same input.

The calculator saves time and reduces markup mistakes by removing the need to memorize wrapper syntax.

• • Seven formats in one place: Switch between HTML, CSS, Markdown, BBCode, LaTeX, Unicode, and ASCII without retyping the same phrase or guessing the wrapper characters.
• • Safe HTML and CSS output: The HTML and CSS branches escape ampersands, angle brackets, and quotes so the underlined string can be pasted into a larger document without breaking surrounding tags.
• • No font required: The Unicode and ASCII formats do not depend on CSS or a particular font, so they survive in plain-text fields, SMS, and older email clients.
• • Built-in character counts: Source code-point and output-length counts make it simple to plan for destination character limits, column widths, or page budgets.

Edit the textarea to update the word, change the dropdown to switch markup, and the calculator regenerates the output in the same pane.

For a sale sign or promotional post that combines an underlined headline with a discount, the Percent Off Calculator handles the percentage math in the same workflow.

The selected format, the receiving platform, and the receiving font all change how the underline looks after you paste.

• • The calculator does not check whether the receiving renderer supports the chosen format. Markdown __text__ renders as bold on GitHub and as underline on Pandoc.
• • The Unicode combining mark U+0332 may render incorrectly in browsers or apps whose font lacks the combining low line glyph, so preview the result in the destination before publishing.
• • The calculator works on a single string. Underlining one word inside a larger paragraph requires manually wrapping that word in the chosen markup and pasting it back into the paragraph.

According to the Unicode Consortium, U+0332 is the COMBINING LOW LINE character that draws a line beneath the preceding base character. Preview the result in the destination before relying on it.

For number-heavy text where you also need digits in plain English, the number to words converter is a useful companion to this calculator.

According to Unicode Consortium, U+0332 is the COMBINING LOW LINE character that draws a line beneath the preceding base character and is part of the Combining Diacritical Marks block.

For number-heavy text where you also need digits in plain English, the Number to Words Converter is a useful companion to this calculator.