In 1851, 284 Evangelicals, 45 Catholics and 32 Jews lived in Sulov, and 179 Evangelicals, 52 Catholics and 5 Jews lived in Hradna.
There were 69 houses with 449 people in Sulov in 1877. In this year, there were 240 residents and 34 houses in Hradna. More detailed information about the population is known from 1900. There were 720 residents in Sulov-Hradna, of which 340 were men and 380 women. There were 8 foreigners registered in the village, two of the local people lived abroad. The numbers of residents are also known by age: there were 133 people up to 6 years, 38 up to 14 years, 66 up to 19 years, 217 up to 39 years, 119 up to 59 years and over 60 years there were 51 people. The population division by their status was as follow: there were 402 single people, 278 people were married and there were 40 widowed people. Twenty people reported Hungarian language as their mother tongue. Seventeen people stated that German is their first language. 676 reported Slovak as their native language and 7 people spoke another unspecified language. 34 people could speak Hungarian. There were 613 Evangelicals, 94 Catholics and 13 Jews. There were 312 literate people in the village. There were 99 houses built in Sulov-Hradna, all of them were covered with shingles. There were only 9 houses built of bricks and stones. The rest of the houses were built of wood. There were 707 residents in Sulov-Hradna in 1920 – 299 men and 408 women. The First World War caused the significant difference between the number of women and men. The statistics show the following ethnic composition: 697 Slovaks, 1 Ruthenian, 1 German and 1 another nationality. According to the religion, the local population consisted of 595 Evangelist, 106 Catholics, 5 Jews and 1 unspecified religion. There were 131 houses in the village.

zdroj: Vlastný výskum autorky textu M. Kerešovej.

Počet obyvateľov obce v roku 1900 rozdelený podľa veku v tabuľke
Magyar statistikai közlemények, Budapest, 1902