Calculate the real distance from a distance measured on a map or drawing, based on the scale.
A scale of "1 : 50,000" means 1 cm on the map equals 50,000 cm in reality — that is, 500 meters. The larger the number after the colon, the more "shrunk" reality is on the map.
Example: on a hiking map with a scale of 1 : 50,000, you measure 5 cm between two cabins. The real distance is then 5 × 50,000 = 250,000 cm, which equals 2,500 meters, or 2.5 km.
It means 1 unit on the map (e.g. 1 cm) equals 50,000 of the same unit in reality. 1 cm on the map is therefore 50,000 cm, or 500 meters, on the ground.
Divide the real distance (in cm) by the scale denominator. To find how far 1,000 meters (100,000 cm) is on a 1:50,000 map, for example, divide 100,000 by 50,000 to get 2 cm.
Hiking maps often use 1:50,000 or 1:25,000 for detailed trail maps, while 1:100,000 or larger is used for broader overview maps. City plans and zoning maps tend to use much smaller denominators, like 1:500 or 1:1,000.