For example, 1: 1 ten thousand, that is, the length of 1 cm on the map is equivalent to 100000 cm on the ground (that is, 1000 m). Strictly speaking, only on a large-scale map representing a small area, because the curvature of the earth is not considered, the scale of the whole map is consistent. The scale usually drawn on the map is called the main scale. On the map, only some lines or points conform to the main scale. The scale is related to the details and accuracy of the map content. Generally speaking, large-scale maps with detailed contents and high geometric accuracy can be used for mapping on maps. Small-scale maps are universal and not suitable for surveying and mapping.

The forms of expression are digital (such as 1: 10000), descriptive (as shown in the figure, 1 cm equals to the field 1000 m) and graphic (divided into linear scale, oblique scale and composite scale). The graphic scale is convenient for measurement. Only on large-scale maps in some areas, the scale is fixed. In addition, only one scale can be used for maps with small or small length deformation. In large areas and maps with large differences between main scale and local scales, it is best to point out some map grids or lines that maintain main scale. Map scale is an indispensable mathematical basis in surveying and mapping and map use, which affects the details of map content. Generally speaking, the larger the map scale, the smaller the error and the higher the measurement accuracy on the map.