The age distribution, , in Oberentfelden is; 708 children or 9.7% of the population are between 0 and 9 years old and 896 teenagers or 12.3% are between 10 and 19. Of the adult population, 908 people or 12.4% of the population are between 20 and 29 years old. 955 people or 13.1% are between 30 and 39, 1,232 people or 16.9% are between 40 and 49, and 991 people or 13.6% are between 50 and 59. The senior population distribution is 791 people or 10.8% of the population are between 60 and 69 years old, 520 people or 7.1% are between 70 and 79, there are 248 people or 3.4% who are between 80 and 89,and there are 49 people or 0.7% who are 90 and older.