(November 2007) India is both a highly rural country, with the large majority of its population living in villages, and home to some of the world's largest metropolitan areas.

The United Nations Population Division places three of India's metros (referred to as "urban agglomerations") in the top 10 in population worldwide: Mumbai (Bombay), Delhi, and Kolkata (Calcutta). The 2001 Indian Census placed the Delhi urban agglomeration (UA) population of 12.9 million third behind the Greater Mumbai UA (16.4 million) and the Kolkata UA (13.2 million). But is Delhi being shortchanged?

A metropolitan area is commonly defined as a central city and its suburban areas and towns, which are often defined by population density and commuting patterns. In India, an urban agglomeration is defined as a continuous urban spread constituting the urban population of a town or city and its adjoining urban outgrowths (OGs), or two or more physically contiguous towns together with their OGs.1 Examples of OGs include railway colonies, university campuses, port areas, and military quarters. There are 384 UAs in India. Sasni UA in the state of Uttar Pradesh is the smallest with a population of 15,258.

Delhi is not a state, but rather the National Capital Territory (NCT), just as Washington, the District of Columbia, is not a state or part of a state in the United States. When the 2001 Census population of the Delhi UA was published, that figure included only the population of the NCT. Since rural populations are not included in a UA population and the NCT does include rural villages, the official Delhi urban population in 2001 was cut from the 2001 Census count of 13,850,507 for the entire NCT to 12,877,470, a loss of nearly 1 million people.

India defines its urban agglomerations in a quirky way: They cannot cross state boundaries. This has no effect upon the population size of Kolkata and Greater Mumbai UA, which are located far from their state borders. But it does affect Delhi.

Any visitor to Delhi would immediately realize that excluding its major suburban industrial and residential areas in neighboring states from the UA population leaves the city at a distinct disadvantage compared to other UAs. When driving from Delhi to contiguous Faridabad city in Haryana state, one scarcely notices any change in the surroundings. But even contiguous suburban cities and towns such as Faridabad and Gurgaon in neighboring Haryana, and Ghaziabad in neighboring Uttar Pradesh, cannot be included in the Delhi UA.

To be fair, we have tried to define the Delhi UA population with the same criteria used to define all other UAs in India. The result (see tables 1 and 3) shows the "redefined" Delhi UA population at 16.2 million in 2001, much larger than the Kolkata UA and nearly as large as the Greater Mumbai UA (see PDFs listed below).

Table 1
Population of Delhi UA, Greater Mumbai UA, and Kolkata UA, 1991 and 2001 Censuses
and 2007 Estimate

Census population (millions)
Average annual growth rate (%) 1991-2001
Estimated ** population (millions) 2007
Urban Agglomeration (UA)
Delhi UA official
Delhi UA "redefined"*
Greater Mumbai UA
Kolkata UA

* Includes areas outside the Delhi NCT in neighboring states added by authors.
** Estimated assuming that the 1991-2001 growth rate has remained constant.
Source: Registrar General of India, 1991 and 2001 censuses and authors' estimates ("redefined" Delhi UA and all 2007 estimates).

That is all well and good for 2001, but what about today? Using our new definition for Delhi UA, its annual 1991-2001 growth rate of 4.7 percent results in a 2007 population of 21.5 million. Using the same method, the Greater Mumbai UA population in 2007 would be 19.3 million. Delhi, in fact, likely passed Mumbai several years ago. Using the same yardstick, Delhi is now India's largest "city."

Delhi, one of the world's oldest cities, became India's capital in 1912 when the British moved the seat of government there from what was then Calcutta. Today, the area has become one of India's most vibrant and fast-growing metros. Cities such as Faridabad and Ghaziabad are now mimicking the well-established corporate and high-tech Gurgaon area in building new high-rise housing. Delhi's new Metro, along with commuter rail lines, are being extended to more distant suburban towns. New special economic zones are being planned in Haryana. There seems to be no end in sight—for Delhi, now India's largest "city."

O.P. Sharma is the Population Reference Bureau's India consultant and former deputy director of census operations in India. He has been involved in all aspects of the Indian census, since the 1951 Census. Carl Haub holds the Conrad Taeuber Chair of Population Information at PRB.

Related Tables

  • Delhi Urban Agglomeration and its Constituent Units, 2001 Census Definition (PDF: 62KB)
  • Delhi Urban Agglomeration and its Constituent Units, 2001 as Redefined (PDF: 58KB)
  • Greater Mumbai Urban Agglomeration and its Constituent Units, 2001 Census (PDF: 43KB)
  • Kolkata Urban Agglomeration and its Constituent Units, 2001 Census (PDF: 77KB)


  1. In India, the "urban" population is defined as persons living in municipalities, large municipal corporations (places with city governments), military quarters, etc.; and persons living in villages of 5,000 or more, at least 75 percent of the male population engaged in nonagricultural pursuits, and a population density of at least 1,000 per square mile. Local census directors may also designate places with distinct urban characteristics but with fewer than 5,000 inhabitants as urban. There were 192 such places at the time of the 2001 Census.