Bilješka: "km2" znači (km)2, kvadratni kilometar ili kilometar kvadratni. Na primjer, 3 km2 je jednako 3×(1,000m)2 = 3,000,000 m2.
Ako je jedan komad zemlje širok pet kilometara, a ima oblik kvadrata i strana kvadrata duga je pet kilometara, to znači da mu je površina 25 km2.
^There are 0.386102159 international square miles in a square kilometre 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. "UnitConversion.org Area Converter". web page. UnitConversion.org. 2009. Pristupljeno 7. 5. 2014.
^An International square mile equals 2.58998811|km2 while the slightly larger US Survey square mile equals 2.58999847|km2. "UnitConversion.org Area Converter". web page. UnitConversion.org. 2009. Pristupljeno 7. 5. 2014.