From a medium-size city of less than 500,000 population in 1947 it grew to well over five million in 1981 and is now estimated to be over 10 million. The area of Karcahi division is about 3,366 sq. km.
The city was formed in 1725 A.D. just a barren piece of land , washed on three sides by the blue waters of the Arabian Sea. A few fishermen lived in a small huts on the sunny creek.
There was a pool of water on this barren piece of land which was known as Kalachi-jo-Kun. Kalachi was the name of fisherman whereas kun meant a deep kitch. Therefore, "Kalachi-jo-Kun" meant the deep ditch of Kalacahi, the fisherman. A few mud huts sprang around this point and their numbers increased, becoming village of Kalachi-jo-Ghote. 
It is locally termed as the City of Lights for its liveliness and the City of The Quaid, for not only being both the birth and death place of Quaid-e-Azam Muhammad Ali Jinnah the founder of Pakistan but also his home after 1947. Residents and those born in the city are called "Karachiites".
The harbor is on the southwest, protected by rocks and an island. Through the city proper flow the Malir River and the Lyari River. The summers are hot and the winters mild, with moderate humidity and the greatest rainfall during a monsoon season.
The Karachi-Peshawar highway links the city with the interior of Pakistan, while the Karachi-O'Mara highway extends along the coast. The Karachi to Zahedan highway connects it with Iran and other Middle Eastern countries.
Karachi is the terminus of Pakistan's long-haul railway system, which mainly serves to transport goods between Karachi and the interior; there is also a circular commuter railroad that also services the port.
Karachi Airport, known as Jinnah Airport, is the largest in the country.
It remains the financial capital, both in terms of production and financial institutions, generating 65% percent of the national revenue providing a Gross Metropolitan Product of PKR. 1.607 trillion or $265 Billion at PPP and a GMP per capita of $21,917.
Most Pakistani banks and corporations are headquartered here, as is the Karachi Stock Exchange. Multinationals also tend to put their Pakistani offices here.