Check out example codes for "h2 in px css". It will help you in understanding the concepts better.

Code Example 1

h1 is   32px   (2em)
h2 is   24px (1.5em)
h3 is 20.8px (1.3em)
h4 is   16px   (1em)
h5 is 12.8px (0.8em)
h6 is 11.2px (0.7em)

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