Calasanz was born in the Dominican Republic, the sixth of eleven children. His parents owned a farm and had high expectations that their son would one day run the family business. In addition to working long hours on the farm, Calasanz did very well in school and took on the responsibility of protecting those around him who were the targets of gangs and bullies. Because he came to the rescue of those who were victimized, many of the townspeople loved and respected him.

As a young man, Calasanz's vision was to become the most educated person in the Dominican Republic. Achieving this goal meant that he would have to leave the farm. Calasanz moved to the city of Santiago and enrolled in a prominent business school. For four years, all he did was work and study. He supported himself by painting cars and making cigars. He studied in the park and slept no more than two hours a night. This grueling schedule did not bother him because he was determined to fulfill his dream.