According to Ministry of Federal Affairs and Local Development Chhathar has an area of 133.93 square kilometres (51.71 sq mi) and the total population of the municipality is 16715 as of Census of Nepal 2011.

[1][2][3] Sudap, Okhare, Phakchamara, Panchakanya Pokhari Hamarjung and Angdim which previously were all separate Village development committee merged to form this new local level body.

Fulfilling the requirement of the new Constitution of Nepal 2015, Ministry of Federal Affairs and Local Development replaced all old VDCs and Municipalities into 753 new local level body (Municipality).

[1][3] At the time of the 2011 Nepal census, Chhathar Rural Municipality had a population of 16,715.

[4] In terms of ethnicity/caste, 41.2% were Limbu, 23.9% Chhetri, 6.9% Hill Brahmin, 4.7% Kami, 3.8% Tamang, 3.4% Newar, 3.2% Sarki, 2.8% Damai/Dholi, 2.8% Magar, 2.0% Gharti/Bhujel, 1.5% Gurung, 1.4% Sherpa, 1.4% Thakuri, 0.3% Sunuwar, 0.2% Terai Brahmin, 0.2% Rai, 0.1% Yadav and 0.4% others.