The age distribution, , in Alt St. Johann is; 159 children or 10.9% of the population are between 0 and 9 years old and 252 teenagers or 17.3% are between 10 and 19. Of the adult population, 178 people or 12.3% of the population are between 20 and 29 years old. 196 people or 13.5% are between 30 and 39, 202 people or 13.9% are between 40 and 49, and 156 people or 10.7% are between 50 and 59. The senior population distribution is 123 people or 8.5% of the population are between 60 and 69 years old, 125 people or 8.6% are between 70 and 79, there are 55 people or 3.8% who are between 80 and 89, and there are 7 people or 0.5% who are between 90 and 99.