Rasagar/Library/PackageCache/com.unity.ugui/Documentation~/TextMeshPro/RichTextSize.md

Font Size

Use the <size> tag to adjust the font size of your text.

You can specify the new size in pixels, font units, or percentage.

Pixel adjustments can be absolute (5px, 10px, and so on) or relative (+1 or -1, for example). Relative sizes are based on the original font size, so they're not cumulative.

Example:

<size=100%>Echo <size=80%>Echo <size=60%>Echo <size=40%>Echo <size=20%>Echo

Adjusting font size