常用长度单位PX/EM/PT/百分比转换公式与对照表
Pixels EMs Percent Points 6px 0.375em 37.50%5pt7px 0.438em 43.80%5pt8px 0.5em 50%6pt9px 0.563em 56.30%7pt10px 0.625em 62.50%8pt11px 0.688em 68.80%8pt12px 0.75em 75%9pt13px 0.813em 81.30%10pt14px 0.875em 87.50%11pt15px 0.938em 93.80%11pt
本表可用的前提是body中的字体设为16px，这也是目前绝大部分浏览器的默认设置 16px 1em 100%12pt17px 1.063em 106.30%13pt18px 1.125em 112.50%14pt19px 1.188em 118.80%14pt20px 1.25em 125%15pt21px 1.313em 131.30%16pt22px 1.375em 137.50%17pt23px 1.438em 143.80%17pt24px 1.5em 150%18pt