The scale of a map allows the person reading it to calculate the size, height and dimensions of the features shown on the map, as well as distances between different points. Maps are scaled down so that they fit on paper. When scaling down a map, every part of the map is scaled by the same amount. The scale on a map is the ratio between real life sizes and how many times it has been shrunk to fit it on the map. This is done to make sure that every object on the map is the same proportion as everything else on the map. Because the Earth is round, and maps are flat, it is impossible to create a map with a perfect scale. Some parts of the map will be too large, while others will be too small.
type of map in the UK, come in several scales.
- Travel maps have a scale of 1:125,000. This means 1 cm on the map represents 125,000 in the real world or 1 cm = 1.25 km. These are used by drivers going long distances.
- Land ranger maps are 1:50,000 (1 cm = 500 m). These are useful for drivers going shorter distances.
- Explorer maps are 1:25,000 (1 cm = 250 m). These are useful for walking and other outdoor pursuits.
- Land plan maps are 1:10,000 (1 cm = 100 m). These show individual streets clearly and might be used by town planners.
The Graphic Method
A Graphic Scale depicts scale using a line, with separations marked by smaller intersecting lines, similar to a ruler. One side of the scale represents the distance on the map, while the other side represents the true distances of objects in real life. By measuring the distance between two objects on a map and then referring to the graphic scale, it is easy to calculate the actual distance between those same items.
There are many benefits to using a graphic scale. First and foremost, it is a straight forward, easy way to determine scale. Secondly, if a map’s size is enlarged or decreased, the scale is also enlarged or reduced, meaning that it is still accurate.
The Verbal Method
The verbal method of depicting scale simply uses words to describe the ratio between the map's scale and the real world. For example, a map might say something like, “one inch equals one hundred and fifty miles.” Calculating scale on a map using the verbal method is easy. Simply measure the distance on the map and then follow the verbal directions to calculate the actual distance.
The Fractional Method
The fractional method for portraying the scale of a map uses a representative fraction to describe the ratio between the map and the real world. This can be shown as 1:50,000 or 1/50,000. In this example, 1 unit of distance on the map represents 50,000 of the same units of distance in the real world. This means that 1 inch on the map represents 50,000 inches in the real world, 1 foot on the map represents 50,000 feet on the map, and so forth.
An introduction video about map scale with a quiz involved too!
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