As 470 km² are covered by forests, lagoons, ponds and salt marshes, the really populated area is 777.8 km².
So the real population density rises to 553 inhabitants/km².

In 1861, the municipalities of the current metropolitan city had 67,063 inhabitants, while the city proper had 33,491.
Since then the city had a population growth of 461%, while the metropolitan municipalities as an all had an increase of 644%.
In that year Cagliari had a population that was the 50% of the metropolitan area, while now it is only the 36%.
As 470 km² are covered by forests, lagoons, ponds and salt marshes, the really populated area is 777.8 km². So the real population density rises to 553 inhabitants/km².
In 1861, the municipalities of the current metropolitan city had 67,063 inhabitants, while the city proper had 33,491. Since then the city had a population growth of 461%, while the metropolitan municipalities as an all had an increase of 644%. In that year Cagliari had a population that was the 50% of the metropolitan area, while now it is only the 36%.
Metropolitan City of Cagliari