Kolačko families are Croats and they are mostly from Ivanec area. In the past century, relatively most of Croatian residents bearing this family name were born in Ivanec area and in Varazdin. In Veliki Gorenec in Lepoglava area every third inhabitant had the family name Kolačko.
Prevalence
About 240 people with faimily name Kolačko live in Croatia today, in 110 households. There were 220 of them in the middle of the past century, and their number increased by 10 percent. They are located in the most of Croatian counties, in 12 cities and 38 other places, mostly in Varazdin (30), Zagreb (30), Lipovnik in Ivanec area (15), Cacinci in Orahovica area (15), and in Koprivnica (15).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over twenty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.