Barangay Calapangan Sur

Barangay Calapangan Sur forms part of Lasam, a municipality in Cagayan, and is classified as a small barangay.

According to the 2020 Philippine census, Barangay Calapangan Sur had a population of 802. This made it the 24th largest of 30 barangays in Lasam by population, placing it among the smaller barangays of the municipality. Residents of Barangay Calapangan Sur accounted for approximately 1.95% of the total population of Lasam, which stood at 41,225 in the same census year.

The barangay recorded 792 residents in the 2015 intercensal count and 802 residents in the 2020 Census — a net change of +1.3%, consistent with a slowly expanding settlement. Barangay Calapangan Sur is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Lasam is a municipality comprising 30 barangays, and serves as the governing unit directly responsible for local services in Barangay Calapangan Sur, including public health, sanitation, peace and order, and civil registration. Within the wider province of Cagayan, which contains 820 barangays across its component cities and municipalities, Barangay Calapangan Sur ranks 605th by 2020 population. Cagayan is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Like every Philippine barangay, Barangay Calapangan Sur is led by an elected Punong Barangay (barangay captain) supported by seven Sangguniang Barangay members (kagawads), an SK Chairperson, a Barangay Secretary, and a Barangay Treasurer. The next Barangay and Sangguniang Kabataan Elections (BSKE) are scheduled for Monday, November 2, 2026, with officials serving four-year terms under Republic Act No. 12232.