Default font sizes for HTML headings

The first post in a potential series to collect short snippets of web search results. This is an experiment to see if it helps better curate my notes. Also looking to for ways to reduce the barrier for writing/posting.

h1 { font-size: 2.0em; /*32.0px*/ }
h2 { font-size: 1.5em; /*24.0px*/ }
h3 { font-size: 1.3em; /*20.8px*/ }
h4 { font-size: 1.0em; /*16.0px*/ }
h5 { font-size: 0.8em; /*12.8px*/ }
h6 { font-size: 0.7em; /*11.2px*/ }