(11/11) Easy Ems to Pixels with 62.5% Font Sizing – UCLA Extension

Convert absolute fonts sizes to relative sizes the easy way with this common CSS typography trick. Since most modern browsers default to a 16 pixel font size, declaring a 62.5% CSS font sizing attribute for the body changes this value to 10 pixels (16 x .625 = 10). The result is that 1em=10px, 1.5em=15px, etc.