Scale of a Map

Three Types of Map Scale.

All maps or charts are drawn to a specific scale. The scale is the relationship between a distance on the map versus the same distance in the real world. A large-scale map shows a small area in great detail, while a small-scale map covers a large area but with little detail. Selecting a map with an appropriate scale is therefore a compromise between coverage and detail, and depends on your intended activity. For example, climbing a mountain with complex topography requires a large-scale map, while a small scale map may be a better choice for a long canoe trip. The scale that you see written on the map is just an approximation. It is never completely constant across the whole map, but varies according to the projection that was used to create the map. The larger the area that a map covers, the more susceptible it is to scale variations. The scale can be expressed as a verbal scale, a ratio scale, or a bar scale.