px:pixel,像素,屏幕上显示的最小单位,用于网页设计,直观方便;
pt:point,是一个标准的长度单位,1pt=1/72英寸,用于印刷业,非常简单易用;
em:即%,在CSS中,1em=100%,是一个比率,结合CSS继承关系使用,具有灵活性。
PPI(DPI):pixel(dot)per inch,每英寸的像素(点)数,是一个率,表示了“清晰度”,“精度”
PX和PT转换的公式:
pt=px乘以3/4。
PX和em转换的公式:
em=16乘以px,也就是说1.5em=1.5×16=24px。
Pixels | 6px | 7px | 8px | 9px | 10px | 11px | 12px | 13px | 14px | 15px | 16px | 17px | 18px | 19px | 20px | 21px | 22px | 23px | 24px |
EMs | 0.375em | 0.438em | 0.5em | 0.563em | 0.625em | 0.688em | 0.75em | 0.813em | 0.875em | 0.938em | 1em | 1.063em | 1.125em | 1.188em | 1.25em | 1.313em | 1.375em | 1.438em | 1.5em |
Percent | 37.5% | 43.8% | 50% | 56.3% | 62.5% | 68.8% | 75% | 81.3% | 87.5% | 93.8% | 100% | 106.3% | 112.5% | 118.8% | 125% | 131.3% | 137.5% | 143.8% | 150% |
Points | 5pt | 5.5pt | 6pt | 7pt | 8pt | 8pt | 9pt | 10pt | 11pt | 11pt | 12pt | 13pt | 14pt | 14pt | 15pt | 16pt | 17pt | 17pt | 18pt |