CSS Unit Converter — px, em, rem, vw, vh, %, pt, cm, mm, in all in one tool

What I built

Added a CSS Unit Converter to devnestio.

👉 https://css-unit-converter-edi.pages.dev

Enter a value, pick a unit, and instantly see conversions to all 10 CSS units. Configurable base font size, viewport, and parent size.

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Supported Units

• px Pixels (absolute)
• em Relative to parent font size
• rem Relative to root font size
• vw Percent of viewport width
• vh Percent of viewport height
• % Percent of parent element
• pt Points (1pt = 1/72 in)
• cm Centimeters
• mm Millimeters
• in Inches

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Features

• Live conversion — all 10 units update as you type
• Configurable base font size, viewport width/height, parent element size
• Copy any value as a CSS-ready string (e.g. 1rem, 14.4vw)
• Formula panel showing the math for each conversion
• Source unit highlighted

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Tech

• Pure Vanilla JS, zero dependencies
• 87 Node.js assert tests covering all conversion formulas and round-trips
• Single HTML file, hosted on Cloudflare Pages

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Try it

👉 CSS Unit Converter

All tools: https://devnestio.pages.dev