The unit mm stands for millimeter. The mm unit in CSS is an absolute unit that can be used to set the size value of an HTML element. The mm unit has a fixed value and does not change. Although the mm unit is rarely used in setting the dimensions of HTML elements, under certain conditions it can be used as a standard size in designing HTML pages. For example, to get the real size of an object in millimeters.
The value depends on the size of the PPI resolution. Conversion is based on the default PPI size of 96 PPI, but can be changed.
The font size or font size can be changed in millimeter units. The smallest value that can be applied is 1mm but with that size the letters will be difficult to read. The normal readable and commonly used size is 5mm.
| PX | MM |
|---|---|
| 1px | 0.264mm |
| 2px | 0.529mm |
| 3px | 0.793mm |
| 4px | 1.058mm |
| 5px | 1.322mm |
| 10px | 2.645mm |
| 15px | 3.968mm |
| 20px | 5.291mm |
| 37.8px | 10mm |
| 50px | 13.229mm |
| 75.59px | 20mm |
| 94.49px | 25mm |
| 100px | 26.458mm |