Kržak families are Croats and they are mostly from Bjelovar. In the past century, relatively most of Croatian residents bearing this family name were born in Bjelovar and Zagreb.
Prevalence
About 90 people with faimily name Kržak live in Croatia today, in 30 households. There were 70 of them in the middle of the past century, and their number increased by 20 percent. They are located in 7 Croatian counties, in 7 cities and 8 other places, mostly in Bjelovar (45), Zagreb (20), Sisak (<5), Velika Gorica (<5), and in Nedelisce in Cakovec area (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.