Mandac families are Croats and they are mostly from Sinj. According to some sources they are from Bosnia. In the past century, relatively most of Croatian residents bearing this family name were born in Sinj and Split.
Prevalence
About 250 people with faimily name Mandac live in Croatia today, in 90 households. There were 130 of them in the middle of the past century, and their number doubled. They are located in two Croatian counties, in 7 cities and 6 other places, mostly in Brnaze (175), Sinj (35), Zagreb (30), Split (30), and in Solin (10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 2007 in source Encyclopaedia of Croatian Surnames.