The economic base of Karaj is its proximity to
Tehran. It is due to the transportation of products between Tehran and the
Caspian Sea. Chemicals, fertilizers and processed agricultural goods are also produced in the city. Zowb Āhan, the avenue leading to an industrial plant, is located at the south of Ostandar Square.
Zowb e Āhan or
Zowb Āhan, literally "steel mill", was a contract between the
Pahlavi government and a consortium from
Nazi Germany. The establishment of the factory
Zowb Āhan e Karaj was halted by the beginning of the
Second World War, and it was never launched. Šahrak-e Jahānšahr was the first modern private industrial and housing complex of Karaj, built in the 1960s. The factories
Jahān Čit (textile factory),
Rowqan Nabāti e Jahān (oil factory), and
Čāy e Jahān (tea factory), were established at the complex. It is one of the largest industrial zones of the nation, with a 20% share of the national GDP. The
special economic zone of Payam, with an area about within the territory of
Payam International Airport, was established in Karaj for development of air cargo and postal transportation, cold store, and packing services, as well as perishable and time sensitive exports. It is the only SEZ in the region with the privilege of its own
airline.
Women's clothing Small and medium women's clothing companies in Karaj produce all kinds of daily clothes and leather boots. Karaj was one of the few Iranian cities in the 2010s that controlled the damage to the
environment in the process of producing women's clothing. Karaj women's over-the-knee boots are exported to the whole country and have a significant contribution to the city's economy. == Transport ==