Css 简明教程
CSS - PX to EM Conversion
单位 px (Pixel) 和 em (indicates size relative to the size of the font) 是长度的两种度量单位。要将 px 转换为 em ，应使用以下公式：
Units px (Pixel) and em (indicates size relative to the size of the font) are two of the measurement units of length. In order to convert px to em, you should use the following formula:
em = px / font-sizeNote ：默认字体大小为 16px 。所以在将 px 转换为 em 时，你需为像素选择基准值（默认值为 16），并在公式中使用该值进行计算。
Note: Default font-size is 16px. So while converting the px to em, you need to select your base value (default is 16) for the pixel and use it in the formula to calculate.
CSS PX to EM Conversion Table
下表显示了 em 值与 px 值之间的对应关系，认为基准像素值为 16px：
Following table shows the corresponding em values to px values, considering the base pixel value as 16px:
PX |
EM |
5px |
0.3125em |
6px |
0.3750em |
7px |
0.4375em |
8px |
0.5000em |
9px |
0.5625em |
10px |
0.6250em |
11px |
0.6875em |
12px |
0.7500em |
13px |
0.8125em |
14px |
0.8750em |
15px |
0.9375em |
16px |
1.0000em |
17px |
1.0625em |
18px |
1.1250em |
19px |
1.1875em |
20px |
1.2500em |
上表仅显示了一些示例值，你可以使用该公式将任何 px 值转换为 em。
The table above shows just few sample values, you may convert any px value to em, using the formula.