What is Map Scale?

Map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. For example, on a 1:100000 scale map, 1cm on the map equals 1km on the ground.

Map scale is often confused or interpreted incorrectly, perhaps because the smaller the map scale, the larger the reference number and vice versa. For example, a 1:100000 scale map is considered a larger scale than a 1:250000 scale map.

Geoscience Australia has complete 'small scale' reference map coverage at scales of 1:2.5, 5, 10 and 20 million. We maintain a complete national topographic map and data coverage at 1:1 million and 1:250000 scale. We have an incomplete map and data coverage at 1:100000 and 1:50000 scales. We also produce digital products for several of these categories as well as a number of themed maps.


Scale Ground distance of 1cm on map Number of maps held by GA Example uses
Largest 1:10000 100m


1:25000
(Local scale)
250m
Bushwalking, in-car navigation, environmental impact assessment, agriculture, emergency response, adventure touring

1:50000
(Local scale)
500m
2338 maps
(limited coverage only)
Bushwalking, fauna surveys, 4 wheel driving, emergency response, adventure touring

1:100000
(Regional scale)
1km 1630 maps
(limited coverage only)
Emergency response, planning, GPS navigation, reports/books, 4 wheel driving, adventure touring

1:250000
(Regional scale)
2.5km 513 maps
(covers Australia)
4 wheel driving, route planning, GPS navigation, mineral exploration, environmental planning, reports/books, emergency management, tourism

1:1 million 10km 49 maps
(covers Australia)
General reference, tourist maps, wall map

1:2.5 million
4 maps
(covers Australia)
General reference, tourist maps, wall map

1:5 million 50km 1 map
(covers Australia)
General reference, tourist maps, wall map
Smallest 1:10 million
100km 1 map
(covers Australia)
General reference, tourist maps, wall map