Font Size Converter
Convert between CSS font size units for responsive web design
For rem calculation
For em calculation
For vw/vh calculation
Common Font Sizes
CSS Font Size Units Explained
px (Pixels)
Absolute unit. 1px equals one device pixel. Doesn't scale with user preferences but provides precise control.
rem (Root Em)
Relative to the root element's font size (usually 16px). Best for consistent, scalable typography. Recommended for modern CSS.
em
Relative to the parent element's font size. Can compound when nested. Good for component-based sizing.
pt (Points)
Traditional print unit. 1pt = 1/72 inch. Use for print stylesheets, not recommended for screen.
vw / vh
Viewport units. 1vw = 1% of viewport width. Great for responsive headlines but needs min/max constraints.
% (Percent)
Relative to parent element. 100% equals parent's font size. Similar to em but expressed as percentage.