Line Height Calculator

Line height—the vertical space between lines of text—is one of the most important factors in typography for readability and visual comfort. Whether you're designing a website, writing a document, or creating any digital content, getting the line height right makes text easier to read and reduces eye fatigue. This tool calculates the optimal line height by multiplying your font size by a chosen ratio, helping you find the perfect balance for different text types.

To use the calculator, enter your font size in pixels and adjust the ratio slider to see real-time results in multiple formats: pixels, unitless values, and em units. The tool provides color-coded recommendations for common use cases—body text typically benefits from 1.5 to 1.6, headings look best at 1.1 to 1.3, and captions work well at 1.3 to 1.4. A live preview shows how your chosen line height affects actual text, so you can see the impact before applying it to your design. All calculations use unitless ratios (like 1.5 instead of pixels), which is the best practice because they scale automatically when font sizes change.

Designers, developers, and content creators use this tool to maintain visual consistency across typography systems and ensure accessibility compliance. The W3C Web Content Accessibility Guidelines recommend a minimum line height of 1.5 for body text to improve readability for all users, including those with dyslexia or visual impairments. By using this calculator regularly, you create type systems that are both aesthetically pleasing and accessible.