100px = 6.25rem

CSS Example

/* 100px as rem */
.element {
  font-size: 6.25rem; /* 100px */
}

When to Use 100px (6.25rem)

A value of 100px (6.25rem) is commonly used for oversized display headings, splash screens, and landing page heroes. In responsive web design, using 6.25rem instead of 100px ensures your jumbo headings scale proportionally when users change their browser font size settings.

Why Use REM?

REM units are relative to the root element's font-size, making them ideal for accessible, responsive designs. When you write 6.25rem instead of 100px, your layout respects user preferences — if someone sets their browser to a larger font size for readability, all your rem-based values scale up proportionally.