3 rem to px = 48px
3 rem equals 48 pixels at the default root font size of 16px. Adjust the root size below to recalculate.
What’s 3rem used for?
3rem (48px at default root) is a typical page-title or hero heading size — large enough to anchor a hero section, restrained enough to remain readable. As space, it's the standard 'extra-large' gap between major page sections. Tailwind's text-5xl and spacing-12 land here.
How it works
To convert 3rem to pixels, multiply by the root font size: 3 × 16 = 48. The rem unit is relative to the root element’s font size, which browsers default to 16px.
3rem at different root sizes
If you’ve overridden the html root font size, the pixel equivalent of 3rem shifts. Here’s 3rem at common root sizes.
| Root size | 3rem in px |
|---|---|
| 16px (default) | 48px |
| 12px | 36px |
| 14px | 42px |
| 18px | 54px |
| 20px | 60px |
| 24px | 72px |
3rem in CSS
Use 3rem as generous section padding on a landing-page block.
.section {
padding-block: 3rem; /* 48px */
}FAQ
Is 3rem the same as 48px?
Yes, at the browser default root font size of 16px. If the root has been changed (some sites use html { font-size: 62.5% } or similar), the conversion changes — see the table above for 3rem at other root sizes.
Why use 3rem instead of 48px?
Because 3rem scales with the user’s browser font-size preference, and 48px does not. If a user enlarges their default font size for accessibility, anything sized in rem scales proportionately — including this value. Use rem for type and type-adjacent properties; reach for px only when the value must stay fixed regardless of user settings.