1.125 rem = 18 px at the standard CSS 96dpi reference.
The conversion uses the fixed relationship 1rem = 16 px (CSS standard: 96px = 72pt, root font size 16px). Your browser may use a different root font size if the site overrides html{font-size}.
| rem | px |
|---|---|
| 0.5 rem | 8 px |
| 0.75 rem | 12 px |
| 1 rem | 16 px |
| 1.25 rem | 20 px |
| 1.5 rem | 24 px |
Use the interactive converter: rem to px converter. Related: px to rem, rem to px, pt to px, px to pt.
For pt and px, yes — CSS fixes 1px = 0.75pt at 96dpi. For rem and em it depends on the font size: 16px is the browser default root, but sites can override it.
Design tools (Illustrator, Word) work in points, while CSS works in px/rem. Converting keeps typography consistent between design handoffs and code.