CSS unit converter
ClientConvert between px, rem, em, and pt—set root and parent font sizes to match your layout.
About CSS unit converter
Convert px, rem, em, and pt with configurable root and parent font sizes—browser-only. 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.
| Unit | Equivalent |
|---|---|
| px | 24px |
| rem | 1.5rem |
| em | 1.5em |
| pt | 18pt |
Converts between px, rem, em, pt using a 16px root for rem and 16px for em. For physical length units, use unit converter.
Nearby workflows on Toolcore
- 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.
- Color converter — HEX, RGB, HSL, OKLCH, named colors—paste a CSS color or use harmonic palette hints. when units or numeric output should be checked on a related calculator.
- Math expression evaluator — Evaluate basic + − × ÷ arithmetic with parentheses in your browser—no variables. when units or numeric output should be checked on a related calculator.
Common use cases
- Translate design tokens from rem to px for a 16px root.
- Compare em sizing against a nested parent font size.
- Quickly check pt values from print specs against px.
Common mistakes to avoid
Assuming every browser uses 16px root
User agent defaults vary—set root font size to match your project.
Mixing with physical units
Use the length unit converter for inches, cm, and meters—not this page.
FAQ
Does this change CSS in my site?
No. It only calculates equivalents in your browser.
Why separate em and rem?
rem uses the root font size; em uses the parent element font size you specify.
Can I paste calc() expressions?
Not yet—enter a single value like 1.25rem or 18px.
More tools
Related utilities you can open in another tab—mostly client-side.
Viewport unit converter
ClientConvert vh, vw, vmin, and vmax to pixels for a chosen viewport width and height—browser-only.
Unit converter (length, temperature, weight)
ClientLength (metric & US customary), temperature (°C, °F, K), and weight (mg to lb)—paste one value, see every column.
Color converter
ClientHEX, RGB, HSL, OKLCH, named colors—paste a CSS color or use harmonic palette hints.
Math expression evaluator
ClientEvaluate basic + − × ÷ arithmetic with parentheses in your browser—no variables.