In the 2016 Census, there were 142 people in Calga. 78.0% of people were born in Australia and 85.5% of people spoke only English at home.
Calga has a number of heritage-listed sites, including:
- Australian Bureau of Statistics (27 June 2017). "Calga(State Suburb)". 2016 Census QuickStats. Retrieved 7 October 2018. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- "Calga Aboriginal Cultural Landscape". New South Wales State Heritage Register. Office of Environment and Heritage. H02014. Retrieved 18 February 2020.