At the time of the 2006 National Census, the city's population was 7,940 in 1,937 households,[7] when it was capital of the former Marhemetabad District of Miandoab County.[8] The following census in 2011 counted 8,681 people in 2,496 households.[9] The 2016 census measured the population of the city as 9,406 people in 2,793 households.[2]
In 2021, the district was separated from the county in the establishment of Chaharborj County, and Chahar Borj was transferred to the new Central District as the county's capital.[5]
^Habibi, Hassan (13 November 2016) [Approved 13 March 1375]. The transformation of Chahar Borj-e Qadim under Miandoab County into a city. rc.majlis.ir (Report) (in Persian). Ministry of the Interior, Political-Defense Commission of the Government Board. Proposal 1.4.42.10871; Notification 3392/T16032K. Archived from the original on 5 February 2013. Retrieved 24 September 2024 – via Research Center of the System of Laws of the Islamic Council of the Farabi Mobile Library.
^Chahar Borj can be found at GEOnet Names Server, at this link, by opening the Advanced Search box, entering "-3057285" in the "Unique Feature Id" form, and clicking on "Search Database".
^Habibi, Hassan (13 December 2005) [Approved 24 September 1369]. Creation and establishment of two counties and several districts and annexation of several villages to Urmia County. rc.majlis.ir (Report) (in Persian). Ministry of the Interior, Defense Political Commission of the Government Board. Proposal 11490.1.4.42; Notification 113478/T188K. Archived from the original on 23 February 2014. Retrieved 20 December 2023 – via Research Center of the System of Laws of the Islamic Council of the Farabi Library of Mobile Users.