Scale map

Each map has a scale that allows us to convert the distances on the map to a real distance.

Scale as a ratio

A simpler definition says that scale gives the ratio of the distance on the map to the real distance. This definition is imprecise, a more precise one is at the end of the article. Usually scale is given either in numerical form or in graphical form. The numerical form is: 1 : 100, it is the ratio mapa : realita. Such a ratio indicates that one centimeter on the map is one hundred centimeters in reality. In other words, one centimetre on the map is equivalent to one metre in reality. A map with the scale 1 : 100 is thus one hundred times smaller than reality.

How to calculate the actual distance

A typical example: you have a map with the scale 1 : 100 000 and you measure a certain distance on it, for example four centimetres. What is the real distance?

You get the distance in centimetres by multiplying your four centimetres by the number after the colon, i.e. 100 000. This gives you the real distance. For our example, we have the result 400 000 cm.

Usually we want to know the distance in other units - either metres or kilometres. To get the length in metres, divide the current result by 100 (because one metre is 100 centimetres). The result is that the distance is equal to 400 000 / 100 = 4 000 meters. To get the result in kilometers, divide the current value in meters by a thousand (because a kilometer is a thousand meters). The result is 4 000 / 1 000 = 4 kilometers.

So the answer is that four centimeters on the map represents four kilometers in reality.

Computer

If you need to convert a distance from a map to an actual distance, you can use the following calculator. In the first box, type the second number from the scale (i.e. if the map has a scale of 1 : 1000, type in a thousand). In the second box, enter the number of centimetres on the map. By default, the computer is loaded with the data to list the previous example, i.e., the scale 1 : 100 000 and 4 centimeters.

How to calculate the distance on the map

You may also need the reverse procedure. You know that a distance is actually equal to 15 kilometers and you want to know what distance it is on a map with the scale 1 : 30 000. In the first step, we convert kilometers to centimeters. When we multiply the kilometers by a thousand, we get the distance in meters: 15 000. If we multiply this number by 100, we get the distance in centimeters: 1 500 000 . In the last step, we just divide this number by the scale, i.e. we calculate 1 500 000 / 30 000 = 50. The result is that 15 kilometres actually corresponds to 50 centimetres on the map.

A more precise definition of scale

Wikipedia says that the scale of a map is the ratio of the reduction of the length measured on the map to the length in reality. What is the difference between this definition and the definition given at the beginning of the article?

The scale problem is related to the curvature of the map itself. Our earth is not flat, it is round. Yet it is impossible to decompose the surface of a sphere into a rectangle so that the resulting rectangle is not distorted. If you took a globe and collapsed its surface, you would not be able to make a rectangle out of the collapsed paper. But a standard map is rectangular - how is that possible? You simply distort some distances to make the surface of the sphere into a rectangular map.

In other words, if we made a huge rectangular map of the whole country at a ratio of 1:1, there would still be distances on that map that would not correspond to reality. Therefore, the scale of the map cannot indicate the ratio of the distance on the map to the real distance, because even on a map created at a 1:1 ratio this would not be true. This problem can be seen nicely in Antarctica, which, if it is on the map, usually looks larger than it is in reality.