There are three main ways that scale is indicated on a map: graphic (or bar), verbal, and representative fraction (RF). Bar scales show scale using a graphic format. The actual length of the bar scale shows what that length represents in real world units.

Types of Map Scale

There are three main types of map scales: verbal scale, graphic scale, and representative fraction. Each of these scales represents the relationship between the distance on the map and the actual distance on the ground.

1. Verbal Scale:
A verbal scale expresses the map scale in words. It describes the relationship between a unit of distance on the map and its corresponding distance on the ground. For example, a verbal scale might be expressed as "1 inch represents 1 mile" or "1 centimeter represents 10 kilometers". Verbal scales are commonly used in maps that are designed for general use, such as road maps or tourist maps.

2. Graphic Scale:
A graphic scale, also known as a bar scale or linear scale, uses a line or bar marked with distance units to represent the scale relationship. The line is divided into equal segments, each representing a specific distance on the ground. Users can measure distances on the map by comparing them to the scale bar. For example, a graphic scale might show that 1 centimeter on the map represents 1 kilometer on the ground. Graphic scales are often found on topographic maps or engineering drawings.

3. Representative Fraction:
A representative fraction (RF) scale, also called a ratio scale, expresses the scale as a fraction or ratio. It represents the relationship between the map distance and the corresponding ground distance in the same unit of measurement. For example, an RF scale of 1:25,000 means that one unit of measurement on the map represents 25,000 units of the same measurement on the ground. RF scales are commonly used in topographic maps and military maps.

Example:
Let's consider a map of a city that uses a verbal scale of "1 inch represents 1 mile". This means that for every inch measured on the map, the equivalent distance on the ground is 1 mile. So, if you measure a distance of 2 inches on the map, it would represent a distance of 2 miles in reality.

In the same scenario, a graphic scale might be included on the map. It could consist of a line divided into segments, with each segment representing 1 mile. By comparing the distance you want to measure on the map to the segments on the scale bar, you can determine the actual ground distance.

Alternatively, the map could use a representative fraction (RF) scale of 1:63,360. This means that one unit of measurement on the map represents 63,360 units of the same measurement on the ground. Therefore, if you measure a distance of 1 inch on the map, it would represent a distance of 63,360 inches (or 1 mile) in reality.

In summary, map scales can be expressed verbally, graphically, or as representative fractions. They provide a way to understand the relationship between distances on a map and their corresponding distances on the ground, allowing users to accurately navigate and measure distances.

Large scale map and Small scale map