Household Size and Distribution As of 2007, there are 9,913 households in Irosin where the average size is 5.04 individuals. There are 4,444 with household size of one to four members, 3,905 household with five to seven members and 1,564 households with more than 8 members. The average family size of the municipality has decreased from 6.02 persons per household in 1975 to 5.82 in 1980 to 5.61 in 1990 to 5.27 in 2000 and to 5.04 persons per household in 2010. The number of households recently registered in 2011 totaled 10,785 with 27% in the urban and 73% in rural areas.


Population Size Irosin has a total population of 51,777 based on the 2010 NSO Census of Population. Irosin comprises 6.99% of the total population of Sorsogon province which is 740,743. Based from the 2000 to 2010 growth rate, the population for the year 2011 is projected to be already 52,444.