At the time of the 2006 National Census, Shadmehr's population was 3,369 in 848 households, when it was a village in Azghand Rural District. The following census in 2011 counted 3,678 people in 1,013 households, by which time the village of Shadmehr had been converted to a city. The 2016 census measured the population of the city as 3,825 people in 1,151 households.
12Davoodi, Parviz (15 February 2009) [تاریخ تصویب (Approval date) 1387/11/27 (Iranian Jalali calendar)]. تصویب نامه در خصوص تبدیل روستای «شادمهر» مرکز بخش شادمهر از توابع شهرستان «مه ولات» در استان خراسان رضوی به شهر[Approval letter regarding the transformation of Shadmehr village, the center of Shadmehr District of Mahvelat County in Razavi Khorasan province, to a city]. لام تا کام [Lam ta Kam] (in Persian). وزارت کشور [Ministry of the Interior]. کمیسیون سیاسی دفاعی هیأت دولت [Political Defense Commission of the Government Board]. شناسه [ID] 5F670D50-742D-424F-A652-25847F88FC88. Archived from the original on 14 June 2025. Retrieved 14 June 2025.
12سرشماري عمومي نفوس و مسكن 1395: استان خراسان رضوی[General Population and Housing Census 2016: Razavi Khorasan Province]. مرکز آمار ایران [Statistical Centre of Iran] (in Persian). Archived from the original(Excel) on 2 April 2022. Retrieved 19 December 2022.
↑Aref, Mohammad Reza (6 March 2005) [تاریخ تصویب (Approval date) 1383.12.16 (Iranian Jalali calendar)]. اصلاحات و تغییرات و تقسیماتی در استان خراسان رضوی[Reforms, changes and divisions in Razavi Khorasan province]. مرکز پژوهشهای مجلس شورای اسلامی ایران [Research Center of the Islamic Consultative Assembly of Iran] (in Persian). وزارت کشور [Ministry of the Interior]. کمیسیون سیاسی دفاعی هیأت دولت [Political Defense Commission of the Government Board]. پیشنهاد شماره [Proposal No.] 1.4.42.26267. Archived from the original on 2 September 2014. Retrieved 12 March 2026.
↑Mousavi, Mir-Hossein (1 July 1987) [تاریخ تصویب (Approval date) 1366.4.10 (Iranian Jalali calendar)]. ایجاد و تشکیل 20 دهستان شامل روستاها، مزارع و مکانها در شهرستان تربت حیدریه تابع استان خراسان[Creation and formation of 20 rural districts including villages, farms and places in Torbat-e Heydarieh County, Khorasan province]. مرکز پژوهشهای مجلس شورای اسلامی ایران [Research Center of the Islamic Consultative Assembly of Iran] (in Persian). وزارت کشور [Ministry of the Interior]. هیات وزیران [Council of Ministers]. پیشنهاد شماره [Proposal No.] 44.1.5.53. Archived from the original on 25 October 2014. Retrieved 5 March 2026.
↑سرشماري عمومي نفوس و مسكن 1385: استان خراسان رضوی[General Population and Housing Census 2006: Razavi Khorasan Province]. مرکز آمار ایران [Statistical Centre of Iran] (in Persian). Archived from the original(Excel) on 20 September 2011. Retrieved 25 September 2022.
↑سرشماري عمومي نفوس و مسكن 1390: استان خراسان رضوی[General Population and Housing Census 2011: Razavi Khorasan Province]. Iran Data Portal—Syracuse University (in Persian). مرکز آمار ایران [Statistical Centre of Iran]. Archived from the original(Excel) on 20 January 2023. Retrieved 19 December 2022.