.class {
font-size: 12px;
}p {
font-size: 150% /*px, cm, in, etc.*/;
}#selector{
font-size:20px;
}// to scale font size in relation to its parent element
style="font-size: 2vw;"<span style="font-size:20px;"></span>p {
font-family: "Times New Roman", Times, serif;
}