As of 2011, Sagauni had a population of 4,507, in 720 households.[2]: 114 This population was 54.3% male (2,446) and 45.7% female (2,061). The 0-6 age group numbered 645 (360 male and 285 female), or 14.3% of the total population. 239 residents were members of Scheduled Castes, or 5.3% of the total.[3]: 94–5
The 1981 census recorded Sagauni as having a population of 2,967 people, in 478 households.[1]: 150–1
The 1961 census recorded Sagauni as comprising 4 hamlets, with a total population of 1,907 people (995 male and 912 female), in 369 households and 267 physical houses. The area of the village was given as 1,527 acres.[4]: lxxx
Infrastructure
As of 2011, Sagauni had 1 primary school; it did not have any healthcare facilities. Drinking water was provided by well, hand pump, and tube well; there were no public toilets. The village had a post office but no public library; there was at least some access to electricity for all purposes. Streets were made of kachcha materials.[2]: 114–9