The regency now covers an area of 4,372.5 square kilometres, and at the 2010 census it had a population of 817,720;[2] at the 2020 Census this had risen to 990,246, of whom 497,314 were males and 492,932 were females;[3] the official estimate as at mid 2023 was 1,035,920 - comprising 521,262 males and 514,658 females.

[1] The table also includes the locations of the district administrative centres, the number of administrative villages in each district (totaling 386 rural desa and 27 urban kelurahan), and its post code.

Six southern districts border directly on the north coast of Lake Toba; from west to east, these are Pematang Silimakuta, Silimakuta, Haranggaol Horison, Dolok Pardamean, Pematang Sidamanik, and Girsang Sipangan Bolon.

Local people mention it as Bukit Kapur Tinggi Raja, but some people have also called it "Kawah Putih" (White Crater), the same name as Kawah Putih in West Java.

The crater is located in Dolok Tinggi Raja Village, 90 kilometres from Medan or 3 to 4 hours drive by motorcycle on the route Medan-Lubuk Pakam-Galang-Bangun Purba-Dolok Tinggi Raja.