"Southern tahsil of Rawalpindi District, Punjab, lying between 33°4′ and 33°26′ N. and 72°56′ and 73°37′ E., with an area of 567 square miles. It is bounded on the east by the Jhelum river, which cuts it off from Kashmir territory. Except for a low ridge of sandstone hills along the Jhelum, the tahsil consists of a plain intersected by numerous ravines. The population in 1901 was 150,566,compared with 152,455 in 1891. It contains 381 villages, of which Gujar Khan is the headquarters. The land revenue and cesses in 1903-4 amounted to 2-7 lakhs."
In the 18th century, Kahuta along with much of the South Asia became part of British India, the undivided tehsil (which includes what is now Kallar Syedan Tehsil) is described in the "Imperial Gazetteer of India" as follows:
Kahuta-Eastern tahsil of Rawalpindi District, Punjab, lying in the Lower Himalayas, between 33° 18′ and 33° 48′ N. and 73° 15′ and 73° 39′ E., with an area of 206 square miles. Its eastern border rests upon the Jhelum River. The whole of the tahsil except the south-west corner lies in the hills, which in the north reach an elevation of over 6,000 feet. The population in 1911 was 94,719, compared with 91,371 in 1891. It contains 231 villages, of which Kahuta is the headquarters. The land revenue and cesses amounted in 1913-4 to 1.2 lakhs.
According to the 1998 census of Pakistan, Kahuta has a total population of 153,000. Many clans are living in Kahuta like Janjua, Abbasis, Siddiquis, Satti, Awan, Malik, Arain,Gakhars, Narma,mughals and many more castes are also present now because city expands day by day but they are smaller in numbers.