CSS px to rem converter

Petr Faltus development

Useful development tool that converts all px definitions in the CSS file body to rem.


Please enter the body of the CSS file. The converter recognizes all valid px definitions (for example 21.9px) and replaces it by calculated rem definitions (for default 16 px/rem for example 1.369rem).

px and rem units

Why not absolute px measurement units but relative rem? The CSS version 3 comes with the rem unit which means root em and which depends on (is relative to) the font-size of the root element. So 1rem means one times the root font-size (which is by default 16px), 2rem means two times, etc. Pages which use in the CSS relative measurement units reflect correct the global resize by the user in his Internet browser setting.

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