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Line-Height Calculator – Find the Optimal Line Spacing for Your Typography

Improve readability with perfectly calculated line spacing using our Line-Height Calculator. Enter your font size and column width to get recommended line-height values in px, em, or unitless — following best practices for body text and headings.

Optimal: 45-75 characters per line

Line-Height Results

Enter font size and click Calculate to see recommendations

Line-Height Best Practices

  • Body text: 1.5-1.6 for optimal readability
  • Headings: 1.1-1.4 (tighter for larger sizes)
  • Measure: 45-75 characters per line is ideal
  • Unitless values: Use unitless (1.5) instead of px for scalable, accessible typography
  • Leading: Space between lines = line-height - font-size

CSS Tip: Always use unitless line-height values (e.g., 1.5) instead of pixels or ems for better inheritance and scalability across different font sizes.