In Croatia, Kastmiller families are Croats (from Bjelovar area ). In the past century, relatively most of Croatian residents bearing this family name were born in Nova Gradiska area.
Prevalence
Only a few people with faimily name Kastmiller live in Croatia today, in two households only. They are located in only one small Croatian place, in Botinac in Bjelovar area (<5).
Outside Croatia
Family name Kastmiller is present in two countries on two continents. The family name "Kastmiller " is used by small number of people in the United States.