Large Scale Maps vs. Small-Scale Maps

Pet peeve time, folks. And it’s one that been getting my goat for years. Maybe it’s my vocation; perhaps I’m too closely tied to the issue to observe it objectively. It’s something, however, I encounter far too often: the inability to determine what constitutes a large-scale map and what constitutes a small-scale map. Here’s a brief gloss-over:


The map of Nakusp (1:20 000) on the left is a large-scale map in relation to the small-scale map of southern British Columbia (1:5 000 000) on the right. Scale ratios are representative fractions. When you see a ratio of 1:20 000, it means that the objects portrayed on the map are drawn at 1/20 000 their actual size. 1/20 000 is a larger fraction than 1/5 000 000, and thus the 1:20 000 map is of a larger scale. One can see how it could be considered somewhat counterintuitive: when you see a large number on a map in the millions, and the area covered by the map is large, you may lean toward that map as being ‘large-scale’ (our brains tend to associate ‘big’ with other things that are ‘big’). But this is incorrect. Those fractions are referring to the size of the object.

In other words: The larger the object appears on the map, the larger the map’s scale is.

Large-scale maps are able to show more detail, since they can ‘zoom in’ on the features being displayed. Smaller-scale maps are more useful for giving broad overviews of large area. As a general rule, large-scale maps are considered to be anything greater than 1: 70 000; medium-scale maps are those between 1:70 000 and 1:400 000; small-scale maps are those beyond 1:400 000 (for example, pretty much anything you’ll find on a world atlas plate; anything beyond 1:1 000 000 is very small).

Further Reading

Compass Dude (n.d.). Map Scale. In ‘Map Reading’, Compass Dude. Available at Accessed 23 November 2010.

Davidson, R. (2002). 5-1. Representative Fraction. In ‘Scale and Distance’, Reading Topographic Maps. Available at Accessed 23 November 2010.

Macquarie University School of Earth Sciences (n.d.). Large scale and small scale. Map Reading Skills Home Page. Available at Accessed 23 November 2010.

Rosenberg, M. (n.d.). Map Scale – Measuring Distance on a Map. Geography. Available at Accessed 23 November 2010.

Wheate, R. (2010). Map Basics. Cartography and Geomatics 205, University of Northern British Columbia. Available at Accessed 23 November 2010.

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