The following is a timeline of the growth of Mumbai's population over the last four centuries:

• 1661: 10000 inhabitants^[1]
• 1664: 15000^[1]
• 1673: 60000^[1] (Fryer)
• 1675: 60000
• 1718: 16000^[1] (Cobbe)
• 1744: 70000^[1] (Niebuhr) (large influx of people during the busy season)
• 1764: 140000^[1] (Niebuhr), According to Historical account pg 6, pop was 60,000
• 1780: 100,000^[1] Materials etc. Part III, pg 525 -- Mahim 13,726
• 1812: 235,000^[1] (Hall) Fixed 165,000, migratory 50,000, famine increase 20,000
• 1814: 180,000 (Warden)
• 1830: 229,000^[1] Lagrange
• 1836: 236,000 "-do-
• 1864: 816,562
• 1872: 644,605^[1] (census)
• 1881: 773,196^[1] (census)
• 1891: 821,764^[1] (census)
• 1901: 812,912 (Greater Bombay)
• 1911: 1,018,388
• 1921: 1,244,934
• 1931: 1,268,936
• 1941: 1,686,127
• 1951: 2,966,902 (0.1% of the world population)
• 1961: 4,152,056
• 1971: 5,970,575
• 1981: 8,227,382
• 1991: 9,900,000 + 2,600,000 (Thané) = 12,500,000 (Greater Bombay)
• 2001: 16,368,084 (Greater Mumbai, incl. Thané)
• 2005: 18,366,089 Greater Mumbai, incl. Thane)
• 2011: 18,410,000
• 2020: 20,411,274