28 px = 1.75 rem at the standard CSS 96dpi reference.
The conversion uses the fixed relationship 1px = 1/16 rem (CSS standard: 96px = 72pt, root font size 16px). Your browser may use a different root font size if the site overrides html{font-size}.
| px | rem |
|---|---|
| 8 px | 0.5 rem |
| 10 px | 0.625 rem |
| 12 px | 0.75 rem |
| 14 px | 0.875 rem |
| 16 px | 1 rem |
Use the interactive converter: px to rem 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.