px to rem converter

Client

Turn design px values into rem for accessible scalable CSS.

How to use

Enter pixels|rootFontSize (root optional).

About px to rem converter

Convert CSS pixels to rem with configurable root font size—local. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.

How to use this page

Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.

32px ÷ 16px root = 2.0000 rem

Nearby workflows on Toolcore

  • rem to px converter — Convert rem to CSS pixels with configurable root font size—browser. when units or numeric output should be checked on a related calculator.
  • CSS unit converter — Convert px, rem, em, and pt with configurable root and parent font sizes—browser-only. when units or numeric output should be checked on a related calculator.
  • Viewport unit converter — Convert vh, vw, vmin, and vmax to pixels for a chosen viewport width and height—browser-only. when units or numeric output should be checked on a related calculator.
  • Unit converter (length, temperature, weight) — Length (metric & US customary), temperature (°C, °F, K), and weight (mg to lb)—paste one value, see every column. when units or numeric output should be checked on a related calculator.

Common use cases

  • Migrate mockup specs to rem-based styles.
  • Match a 10px root design system.

Common mistakes to avoid

  • Root size

    Default root is 16px; override if your html font-size differs.

FAQ

em vs rem?

rem is relative to root; this tool outputs rem only.

More tools

Related utilities you can open in another tab—mostly client-side.