# Em

A unit equal to the font size.

**Source:** “A unit of measurement, 1em is equal to the size of a font. Adjusting font size will resize glyphs relative to the em square.” [Introducing type - Fonts Knowledge (Google Fonts)](https://fonts.google.com/knowledge/introducing_type)

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Published 2026-10-29. Web page: https://www.mackenziebowes.com/reference/glossary/em