The age distribution, , in Boniswil is; 136 children or 9.7% of the population are between 0 and 9 years old and 191 teenagers or 13.6% are between 10 and 19. Of the adult population, 156 people or 11.1% of the population are between 20 and 29 years old. 175 people or 12.4% are between 30 and 39, 246 people or 17.5% are between 40 and 49, and 231 people or 16.4% are between 50 and 59. The senior population distribution is 143 people or 10.1% of the population are between 60 and 69 years old, 92 people or 6.5% are between 70 and 79, there are 31 people or 2.2% who are between 80 and 89,and there are 8 people or 0.6% who are 90 and older.