Pixels vs REM vs EM: Breaking down CSS Sizes

px to rem  When to use Rem, Em, VWVH, %, PX? · Use REM so your app can scale based on the root font size using media queries · Use EM for margins under While PX, EM, and REM are primarily used for font sizing, %, VW, and VH are mostly used for margins, padding, spacing, and widthsheights

Easy converter tool to turn rem into px or px into rem in a few seconds  postcss-rem-to-pixel-next Convert rem units to px units using PostCSS Based on postcss-pxtorem

Pixel to Em Converter The tool below allows you to work out the em sizes from pixels Set a default pixel size for body PX are absolute units that remain constant in size It is the smallest addressable element in a raster image On the other hand, Rem is usually used in CSS