The symbol "km2" means (km)2, square kilometre or kilometre squared and not k(m2), kilo–square metre. For example, 3 km2 is equal to 3×(1,000m)2 = 3,000,000 m2, not 3,000 m2.
Part of an Ordnance Survey map, published 1952. The grid lines are at one-kilometre intervals, giving each square an area of one square kilometre. The map shows that the area of the island is about two square kilometres.
Topographical map grids are worked out in metres, with the grid lines being 1,000 metres apart.
1:100,000 maps are divided into squares representing 1 km2, each square on the map being one square centimetre in area and representing 1 km2 on the surface of the Earth.
For 1:50,000 maps, the grid lines are 2 cm apart. Each square on the map is 2 cm by 2 cm (4 cm2) and represents 1 km2 on the surface of the Earth.
For 1:25,000 maps, the grid lines are 4 cm apart. Each square on the map is 4 cm by 4 cm (16 cm2) and represents 1 km2 on the surface of the Earth.
In each case, the grid lines enclose one square kilometre.
Map of Delft, Netherlands, dated 1659. The walls enclosed an area of about 1 square kilometre.
The area enclosed by the walls of many European medieval cities were about one square kilometre. These walls are often either still standing or the route they followed is still clearly visible, such as in Brussels, where the wall has been replaced by a ring road, or in Frankfurt, where the wall has been replaced by gardens. The approximate area of the old walled cities can often be worked out by fitting the course of the wall to a rectangle or an oval (ellipse). Examples include:
The medieval city of Bruges, a major centre in Flanders, was roughly oval or elliptical in shape with the longer or semi-major axis running north and south.
The maximum distance from north to south (semi-major axis) is 2.53 kilometres (1.57 mi).[6]
The maximum distance from east to west (semi-minor axis) is 1.81 kilometres (1.12 mi).[6]
A perfect ellipse of these dimensions would be 2.53 × 1.81 × (π/4) = 3.597 km2.
Using the figures published by golf course architects Crafter and Mogford, a course should have a fairway width of 120 metres and 40 metres clear beyond the hole. Assuming a 6,000-metre (6,600 yd) 18-hole course, an area of 80 hectares (0.8 square kilometre) needs to be allocated for the course itself.[17][Note 1] Examples of golf courses that are about one square kilometre include:
^Assume that each hole requires (6000÷18 + 40) = 373 metres in length. The area needed is (18 × 373 × 120 ÷ 10,000) = 80.64 ha (1 hectare = 10,000 square metres).
^There are 0.386102159 international square miles in a square kilometer while there are 0.386100614 US Survey square miles in the same measure. This is because the US Survey measures are very slightly larger than the international measures.[1]
^There are 247.105381467 international acres in a square kilometre while there are only 247.104393047 of the very slightly larger US Survey acres.[1]
^An International square mile equals 2.58998811km2 while the slightly larger US Survey square mile equals 2.58999847km2.[1]
^"Arabian Ranches Golf Club". 7 Days in Dubai. Catchpole Communications FZ-LLC, Al Sidra Media LLC. Archived from the original on 2012-09-08. Retrieved 1 April 2018.
^"MauritiusAttraction". Amity Institute of Higher Education, Mauritius. Amity Institute of Higher Education. 2011. Archived from the original on 12 October 2013. Retrieved 27 June 2013.
