ವಿಕಿಪೀಡಿಯ:WikiProject Geographical coordinates/dim:

The dim: parameter specifies the width of the object in metres or kilometres, overriding the scale implied by any type: parameter.

Syntax — dim:<width><units>

width — integer number of metres (m) or kilometres (km)
units — m or km, if not specified, defaults to m

GeoHack uses dim: to select a map scale. If no dim:, type:, or scale: parameters are provided, GeoHack uses its default scale of 1:300,000.

Samples
Subject Dim Markup Result
Buckingham Palace 120m {{coord|51.501|-0.142|dim:120m}} 51°30′04″N 0°08′31″W / 51.501°N 0.142°W / 51.501; -0.142
London 10km {{coord|51.507222|-0.1275|dim:10km}} 51°30′26″N 0°07′39″W / 51.507222°N 0.1275°W / 51.507222; -0.1275