The age distribution, , in Untereggen is; 171 children or 19.1% of the population are between 0 and 9 years old and 131 teenagers or 14.6% are between 10 and 19. Of the adult population, 69 people or 7.7% of the population are between 20 and 29 years old.
The age distribution in Untereggen shows that 19.1% of the population is under 10 years old, with 171 children.  Additionally, 14.6% of the population is between 10 and 19 years old, comprising 131 teenagers. Finally, 7.7% of the adult population, or 69 people, are aged 20 to 29.