Convert between CSS units like px, rem, em, vw, vh, and percentages. Essential for responsive web design.
Want to jump straight in? Use our free CSS Unit Converter tool directly.
Navigate to the CSS Unit Converter on UtilsNow. Convert between all CSS length units.
Type a number and select the source unit (px, rem, em, pt, vw, vh, %, etc.).
For rem and em conversions, set the base font size (default is 16px). This affects the conversion ratio.
The tool shows the equivalent value in all CSS units simultaneously, making it easy to compare.
Copy the converted CSS value including the unit suffix, ready to paste into your stylesheet.
Use our free CSS Unit Converter tool — no signup, no uploads, works directly in your browser.
Open CSS Unit Converterrem is relative to the root (html) font size. em is relative to the parent element font size. rem is more predictable and generally preferred.
Use rem for font sizes and spacing (respects user font size preferences). Use px for borders and very small fixed-size elements.
Divide the pixel value by the base font size (default 16px). For example: 24px / 16 = 1.5rem.